foo.cc: In function ‘int main()’:
foo.cc:18:20: error: no match for ‘operator>>’ (operand types are ‘std::istream’ {aka ‘std::basic_istream<char>’} and ‘st’)
   18 |                 cin>>a[i];
      |                 ~~~^~~~~~
      |                 |       |
      |                 |       st
      |                 std::istream {aka std::basic_istream<char>}
foo.cc:18:20: note: there are 68 candidates
   18 |                 cin>>a[i];
      |                 ~~~^~~~~~
In file included from /nix/gcc-15.2.0/include/c++/15.2.0/sstream:42,
                 from /nix/gcc-15.2.0/include/c++/15.2.0/complex:50,
                 from /nix/gcc-15.2.0/include/c++/15.2.0/ccomplex:43,
                 from stdc++.h:133:
/nix/gcc-15.2.0/include/c++/15.2.0/istream:172:7: note: candidate 1: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  172 |       operator>>(bool& __n)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:172:24: note: no known conversion for argument 1 from ‘st’ to ‘bool&’
  172 |       operator>>(bool& __n)
      |                  ~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:176:7: note: candidate 2: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]’
  176 |       operator>>(short& __n);
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:176:25: note: no known conversion for argument 1 from ‘st’ to ‘short int&’
  176 |       operator>>(short& __n);
      |                  ~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:179:7: note: candidate 3: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  179 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:179:34: note: no known conversion for argument 1 from ‘st’ to ‘short unsigned int&’
  179 |       operator>>(unsigned short& __n)
      |                  ~~~~~~~~~~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:183:7: note: candidate 4: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]’
  183 |       operator>>(int& __n);
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:183:23: note: no known conversion for argument 1 from ‘st’ to ‘int&’
  183 |       operator>>(int& __n);
      |                  ~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:186:7: note: candidate 5: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  186 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:186:32: note: no known conversion for argument 1 from ‘st’ to ‘unsigned int&’
  186 |       operator>>(unsigned int& __n)
      |                  ~~~~~~~~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:190:7: note: candidate 6: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  190 |       operator>>(long& __n)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:190:24: note: no known conversion for argument 1 from ‘st’ to ‘long int&’
  190 |       operator>>(long& __n)
      |                  ~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:194:7: note: candidate 7: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  194 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:194:33: note: no known conversion for argument 1 from ‘st’ to ‘long unsigned int&’
  194 |       operator>>(unsigned long& __n)
      |                  ~~~~~~~~~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:201:7: note: candidate 8: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  201 |       operator>>(long long& __n)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:201:29: note: no known conversion for argument 1 from ‘st’ to ‘long long int&’
  201 |       operator>>(long long& __n)
      |                  ~~~~~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:205:7: note: candidate 9: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  205 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:205:38: note: no known conversion for argument 1 from ‘st’ to ‘long long unsigned int&’
  205 |       operator>>(unsigned long long& __n)
      |                  ~~~~~~~~~~~~~~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:221:7: note: candidate 10: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  221 |       operator>>(float& __f)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:221:25: note: no known conversion for argument 1 from ‘st’ to ‘float&’
  221 |       operator>>(float& __f)
      |                  ~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:225:7: note: candidate 11: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  225 |       operator>>(double& __f)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:225:26: note: no known conversion for argument 1 from ‘st’ to ‘double&’
  225 |       operator>>(double& __f)
      |                  ~~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:229:7: note: candidate 12: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  229 |       operator>>(long double& __f)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:229:31: note: no known conversion for argument 1 from ‘st’ to ‘long double&’
  229 |       operator>>(long double& __f)
      |                  ~~~~~~~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:330:7: note: candidate 13: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  330 |       operator>>(void*& __p)
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:330:25: note: no known conversion for argument 1 from ‘st’ to ‘void*&’
  330 |       operator>>(void*& __p)
      |                  ~~~~~~~^~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:124:7: note: candidate 14: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  124 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:124:36: note: no known conversion for argument 1 from ‘st’ to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)’ {aka ‘std::basic_istream<char>& (*)(std::basic_istream<char>&)’}
  124 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |                  ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:128:7: note: candidate 15: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>; __ios_type = std::basic_ios<char>]’
  128 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:128:32: note: no known conversion for argument 1 from ‘st’ to ‘std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&)’ {aka ‘std::basic_ios<char>& (*)(std::basic_ios<char>&)’}
  128 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |                  ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:135:7: note: candidate 16: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]’
  135 |       operator>>(ios_base& (*__pf)(ios_base&))
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:135:30: note: no known conversion for argument 1 from ‘st’ to ‘std::ios_base& (*)(std::ios_base&)’
  135 |       operator>>(ios_base& (*__pf)(ios_base&))
      |                  ~~~~~~~~~~~~^~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:354:7: note: candidate 17: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; __streambuf_type = std::basic_streambuf<char>]’
  354 |       operator>>(__streambuf_type* __sb);
      |       ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:354:36: note: no known conversion for argument 1 from ‘st’ to ‘std::basic_istream<char>::__streambuf_type*’ {aka ‘std::basic_streambuf<char>*’}
  354 |       operator>>(__streambuf_type* __sb);
      |                  ~~~~~~~~~~~~~~~~~~^~~~
In file included from /nix/gcc-15.2.0/include/c++/15.2.0/string:57,
                 from /nix/gcc-15.2.0/include/c++/15.2.0/bitset:54,
                 from stdc++.h:54:
/nix/gcc-15.2.0/include/c++/15.2.0/bits/basic_string.tcc:866:5: note: candidate 18: ‘template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, __cxx11::basic_string<_CharT, _Traits, _Alloc>&)’
  866 |     operator>>(basic_istream<_CharT, _Traits>& __in,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/basic_string.tcc:866:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bitset:1602:5: note: candidate 19: ‘template<class _CharT, class _Traits, long unsigned int _Nb> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, bitset<_Nb>&)’
 1602 |     operator>>(std::basic_istream<_CharT, _Traits>& __is, bitset<_Nb>& __x)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bitset:1602:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::bitset<_Nb>’
   18 |                 cin>>a[i];
      |                         ^
In file included from /nix/gcc-15.2.0/include/c++/15.2.0/istream:1111:
/nix/gcc-15.2.0/include/c++/15.2.0/bits/istream.tcc:983:5: note: candidate 20: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _CharT&)’
  983 |     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/istream.tcc:983:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   deduced conflicting types for parameter ‘_CharT’ (‘char’ and ‘st’)
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/istream:851:5: note: candidate 21: ‘template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(basic_istream<char, _Traits>&, unsigned char&)’
  851 |     operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:851:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘unsigned char&’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/istream:856:5: note: candidate 22: ‘template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(basic_istream<char, _Traits>&, signed char&)’
  856 |     operator>>(basic_istream<char, _Traits>& __in, signed char& __c)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:856:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘signed char&’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/istream:898:5: note: candidate 23: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _CharT*)’
  898 |     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:898:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   mismatched types ‘_CharT*’ and ‘st’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/istream:941:5: note: candidate 24: ‘template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(basic_istream<char, _Traits>&, unsigned char*)’
  941 |     operator>>(basic_istream<char, _Traits>& __in, unsigned char* __s)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:941:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘unsigned char*’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/istream:947:5: note: candidate 25: ‘template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(basic_istream<char, _Traits>&, signed char*)’
  947 |     operator>>(basic_istream<char, _Traits>& __in, signed char* __s)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:947:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘signed char*’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/istream:1101:5: note: candidate 26: ‘template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&)’
 1101 |     operator>>(_Istream&& __is, _Tp&& __x)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/istream:1101:5: note: template argument deduction/substitution failed:
/nix/gcc-15.2.0/include/c++/15.2.0/istream: In substitution of ‘template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&) [with _Istream = std::basic_istream<char>&; _Tp = st&]’:
foo.cc:18:11:   required from here
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/istream:1101:5: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
 1101 |     operator>>(_Istream&& __is, _Tp&& __x)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/complex:543:5: note: candidate 27: ‘template<class _Tp, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, complex<_Tp>&)’
  543 |     operator>>(basic_istream<_CharT, _Traits>& __is, complex<_Tp>& __x)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/complex:543:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::complex<_Tp>’
   18 |                 cin>>a[i];
      |                         ^
In file included from stdc++.h:146:
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:81:5: note: candidate 28: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Resetiosflags)’
   81 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Resetiosflags __f)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:81:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘std::_Resetiosflags’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:111:5: note: candidate 29: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Setiosflags)’
  111 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Setiosflags __f)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:111:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘std::_Setiosflags’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:142:5: note: candidate 30: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Setbase)’
  142 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Setbase __f)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:142:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘std::_Setbase’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:182:5: note: candidate 31: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Setfill<_CharT>)’
  182 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Setfill<_CharT> __f)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:182:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::_Setfill<_CharT>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:212:5: note: candidate 32: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Setprecision)’
  212 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Setprecision __f)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:212:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘std::_Setprecision’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:242:5: note: candidate 33: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Setw)’
  242 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Setw __f)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:242:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘std::_Setw’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:276:5: note: candidate 34: ‘template<class _CharT, class _Traits, class _MoneyT> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Get_money<_MoneyT>)’
  276 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Get_money<_MoneyT> __f)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:276:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::_Get_money<_MoneyT>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:430:5: note: candidate 35: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Get_time<_CharT>)’
  430 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Get_time<_CharT> __f)
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/iomanip:430:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::_Get_time<_CharT>’
   18 |                 cin>>a[i];
      |                         ^
In file included from /nix/gcc-15.2.0/include/c++/15.2.0/valarray:607,
                 from stdc++.h:169:
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: candidate 36: ‘template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__shift_right, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__shift_right, typename _Dom1::value_type>::result_type> std::operator>>(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)’
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(>>, struct std::__shift_right)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘std::istream’ {aka ‘std::basic_istream<char>’} is not derived from ‘const std::_Expr<_Dom1, typename _Dom1::value_type>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: candidate 37: ‘template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__shift_right, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__shift_right, typename _Dom1::value_type>::result_type> std::operator>>(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)’
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(>>, struct std::__shift_right)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘std::istream’ {aka ‘std::basic_istream<char>’} is not derived from ‘const std::_Expr<_Dom1, typename _Dom1::value_type>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: candidate 38: ‘template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__shift_right, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__shift_right, typename _Dom1::value_type>::result_type> std::operator>>(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)’
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(>>, struct std::__shift_right)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘const std::_Expr<_Dom1, typename _Dom1::value_type>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: candidate 39: ‘template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__shift_right, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__shift_right, typename _Dom1::value_type>::result_type> std::operator>>(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)’
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(>>, struct std::__shift_right)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘std::istream’ {aka ‘std::basic_istream<char>’} is not derived from ‘const std::_Expr<_Dom1, typename _Dom1::value_type>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: candidate 40: ‘template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__shift_right, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__shift_right, typename _Dom1::value_type>::result_type> std::operator>>(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)’
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(>>, struct std::__shift_right)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/valarray_after.h:416:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘const std::_Expr<_Dom1, typename _Dom1::value_type>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/valarray:1207:1: note: candidate 41: ‘template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__shift_right, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__shift_right, _Tp>::result_type> std::operator>>(const valarray<_Tp>&, const valarray<_Tp>&)’
 1207 | _DEFINE_BINARY_OPERATOR(>>, __shift_right)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/valarray:1207:1: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘std::istream’ {aka ‘std::basic_istream<char>’} is not derived from ‘const std::valarray<_Tp>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/valarray:1207:1: note: candidate 42: ‘template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__shift_right, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__shift_right, _Tp>::result_type> std::operator>>(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)’
 1207 | _DEFINE_BINARY_OPERATOR(>>, __shift_right)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/valarray:1207:1: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘std::istream’ {aka ‘std::basic_istream<char>’} is not derived from ‘const std::valarray<_Tp>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/valarray:1207:1: note: candidate 43: ‘template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__shift_right, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__shift_right, _Tp>::result_type> std::operator>>(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)’
 1207 | _DEFINE_BINARY_OPERATOR(>>, __shift_right)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/valarray:1207:1: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘const std::valarray<_Tp>’
   18 |                 cin>>a[i];
      |                         ^
In file included from /nix/gcc-15.2.0/include/c++/15.2.0/random:52,
                 from stdc++.h:182:
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:930:5: note: candidate 44: ‘template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, uniform_int_distribution<_IntType>&)’
  930 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:930:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::uniform_int_distribution<_IntType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:991:5: note: candidate 45: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, uniform_real_distribution<_IntType>&)’
  991 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:991:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::uniform_real_distribution<_IntType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2168:5: note: candidate 46: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, cauchy_distribution<_RealType>&)’
 2168 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2168:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::cauchy_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
In file included from /nix/gcc-15.2.0/include/c++/15.2.0/random:50:
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.h:3932:5: note: candidate 47: ‘template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, bernoulli_distribution&)’
 3932 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.h:3932:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   cannot convert ‘a[i]’ (type ‘st’) to type ‘std::bernoulli_distribution&’
   18 |                 cin>>a[i];
      |                      ~~~^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1133:5: note: candidate 48: ‘template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, geometric_distribution<_IntType>&)’
 1133 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1133:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::geometric_distribution<_IntType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1784:5: note: candidate 49: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, exponential_distribution<_RealType>&)’
 1784 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1784:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::exponential_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2562:5: note: candidate 50: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, weibull_distribution<_RealType>&)’
 2562 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2562:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::weibull_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2636:5: note: candidate 51: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, extreme_value_distribution<_RealType>&)’
 2636 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2636:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::extreme_value_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:177:5: note: candidate 52: ‘template<class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, linear_congruential_engine<_UIntType, __a, __c, __m>&)’
  177 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:177:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::linear_congruential_engine<_UIntType, __a, __c, __m>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:504:5: note: candidate 53: ‘template<class _UIntType1, long unsigned int __w1, long unsigned int __n1, long unsigned int __m1, long unsigned int __r1, _UIntType1 __a1, long unsigned int __u1, _UIntType1 __d1, long unsigned int __s1, _UIntType1 __b1, long unsigned int __t1, _UIntType1 __c1, long unsigned int __l1, _UIntType1 __f1, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>&)’
  504 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:504:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:659:5: note: candidate 54: ‘template<class _UIntType, long unsigned int __w, long unsigned int __s, long unsigned int __r, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, subtract_with_carry_engine<_UIntType, __w, __s, __r>&)’
  659 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:659:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::subtract_with_carry_engine<_UIntType, __w, __s, __r>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:726:5: note: candidate 55: ‘template<class _RandomNumberEngine, long unsigned int __p, long unsigned int __r, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, discard_block_engine<_RandomNumberEngine, __p, __r>&)’
  726 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:726:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::discard_block_engine<_RandomNumberEngine, __p, __r>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:890:5: note: candidate 56: ‘template<class _RandomNumberEngine, long unsigned int __k, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, shuffle_order_engine<_RandomNumberEngine, __k>&)’
  890 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:890:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::shuffle_order_engine<_RandomNumberEngine, __k>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1248:5: note: candidate 57: ‘template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, negative_binomial_distribution<_IntType>&)’
 1248 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1248:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::negative_binomial_distribution<_IntType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1458:5: note: candidate 58: ‘template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, poisson_distribution<_IntType>&)’
 1458 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1458:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::poisson_distribution<_IntType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1725:5: note: candidate 59: ‘template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, binomial_distribution<_IntType>&)’
 1725 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1725:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::binomial_distribution<_IntType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1946:5: note: candidate 60: ‘template<class _RealType1, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, normal_distribution<_RealType>&)’
 1946 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:1946:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::normal_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2011:5: note: candidate 61: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, lognormal_distribution<_RealType>&)’
 2011 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2011:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::lognormal_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2082:5: note: candidate 62: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, chi_squared_distribution<_RealType>&)’
 2082 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2082:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::chi_squared_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2244:5: note: candidate 63: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, fisher_f_distribution<_RealType>&)’
 2244 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2244:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::fisher_f_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2317:5: note: candidate 64: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, student_t_distribution<_RealType>&)’
 2317 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2317:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::student_t_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2487:5: note: candidate 65: ‘template<class _RealType1, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, gamma_distribution<_RealType>&)’
 2487 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2487:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::gamma_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2795:5: note: candidate 66: ‘template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, discrete_distribution<_IntType>&)’
 2795 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:2795:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::discrete_distribution<_IntType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:3002:5: note: candidate 67: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, piecewise_constant_distribution<_RealType>&)’
 3002 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:3002:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::piecewise_constant_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:3208:5: note: candidate 68: ‘template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, piecewise_linear_distribution<_RealType>&)’
 3208 |     operator>>(std::basic_istream<_CharT, _Traits>& __is,
      |     ^~~~~~~~
/nix/gcc-15.2.0/include/c++/15.2.0/bits/random.tcc:3208:5: note: template argument deduction/substitution failed:
foo.cc:18:25: note:   ‘st’ is not derived from ‘std::piecewise_linear_distribution<_RealType>’
   18 |                 cin>>a[i];
      |                         ^
foo.cc:19:22: error: ‘struct st’ has no member named ‘qh’; did you mean ‘xh’?
   19 |                 a[i].qh=i;
      |                      ^~
      |                      xh
foo.cc:23:28: error: ‘struct st’ has no member named ‘qh’; did you mean ‘xh’?
   23 |                 cout<<a[i].qh<<' ';
      |                            ^~
      |                            xh