/in/foo.cc:6:27: error: 'long long int y1' redeclared as different kind of symbol
 int p[1919810],n,m,ans,x1,y1,x2,y2;
                           ^~
In file included from /usr/include/features.h:364:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/os_defines.h:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/c++config.h:507,
                 from /usr/include/c++/6/cassert:43,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:33,
                 from /in/foo.cc:1:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:251:1: note: previous declaration 'double y1(double)'
 __MATHCALL (y1,, (_Mdouble_));
 ^
/in/foo.cc: In function 'void merge(long long int, long long int)':
/in/foo.cc:15:23: error: no matching function for call to 'find()'
     p[find(x)] = find();
                       ^
/in/foo.cc:10:5: note: candidate: long long int find(long long int)
 int find(int x){
     ^~~~
/in/foo.cc:10:5: note:   candidate expects 1 argument, 0 provided
In file included from /usr/include/c++/6/algorithm:62:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:65,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/stl_algo.h:3784:5: note: candidate: template<class _IIter, class _Tp> _IIter std::find(_IIter, _IIter, const _Tp&)
     find(_InputIterator __first, _InputIterator __last,
     ^~~~
/usr/include/c++/6/bits/stl_algo.h:3784:5: note:   template argument deduction/substitution failed:
/in/foo.cc:15:23: note:   candidate expects 3 arguments, 0 provided
     p[find(x)] = find();
                       ^
In file included from /usr/include/c++/6/bits/locale_facets.h:48:0,
                 from /usr/include/c++/6/bits/basic_ios.h:37,
                 from /usr/include/c++/6/ios:44,
                 from /usr/include/c++/6/istream:38,
                 from /usr/include/c++/6/sstream:38,
                 from /usr/include/c++/6/complex:45,
                 from /usr/include/c++/6/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/streambuf_iterator.h:369:5: note: candidate: template<class _CharT2> typename __gnu_cxx::__enable_if<std::__is_char<_CharT2>::__value, std::istreambuf_iterator<_CharT> >::__type std::find(std::istreambuf_iterator<_CharT>, std::istreambuf_iterator<_CharT>, const _CharT2&)
     find(istreambuf_iterator<_CharT> __first,
     ^~~~
/usr/include/c++/6/bits/streambuf_iterator.h:369:5: note:   template argument deduction/substitution failed:
/in/foo.cc:15:23: note:   candidate expects 3 arguments, 0 provided
     p[find(x)] = find();
                       ^
/in/foo.cc: At global scope:
/in/foo.cc:17:10: error: '::main' must return 'int'
 int main(){
          ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:20:21: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}' and 'double(double) throw ()')
     while(cin >> x1 >> y1 >> x2 >> y2) merge(f(x1, y1),f(x2, y2));
           ~~~~~~~~~~^~~~~
In file included from /usr/include/c++/6/sstream:38:0,
                 from /usr/include/c++/6/complex:45,
                 from /usr/include/c++/6/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
                 from /in/foo.cc:1:
/usr/include/c++/6/istream:120:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
       operator>>(__istream_type& (*__pf)(__istream_type&))
       ^~~~~~~~
/usr/include/c++/6/istream:120:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:20:24: error: invalid conversion from 'double (*)(double) throw ()' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}' [-fpermissive]
     while(cin >> x1 >> y1 >> x2 >> y2) merge(f(x1, y1),f(x2, y2));
                        ^~
In file included from /usr/include/c++/6/sstream:38:0,
                 from /usr/include/c++/6/complex:45,
                 from /usr/include/c++/6/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
                 from /in/foo.cc:1:
/usr/include/c++/6/istream:124:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>] <near match>
       operator>>(__ios_type& (*__pf)(__ios_type&))
       ^~~~~~~~
/usr/include/c++/6/istream:124:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:20:24: error: invalid conversion from 'double (*)(double) throw ()' to 'std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}' [-fpermissive]
     while(cin >> x1 >> y1 >> x2 >> y2) merge(f(x1, y1),f(x2, y2));
                        ^~
In file included from /usr/include/c++/6/sstream:38:0,
                 from /usr/include/c++/6/complex:45,
                 from /usr/include/c++/6/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
                 from /in/foo.cc:1:
/usr/include/c++/6/istream:131:7: note: candidate: 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>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
       operator>>(ios_base& (*__pf)(ios_base&))
       ^~~~~~~~
/usr/include/c++/6/istream:131:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:20:24: error: invalid conversion from 'double (*)(double) throw ()' to 'std::ios_base& (*)(std::ios_base&)' [-fpermissive]
     while(cin >> x1 >> y1 >> x2 >> y2) merge(f(x1, y1),f(x2, y2));
                        ^~
In file included from /usr/include/c++/6/sstream:38:0,
                 from /usr/include/c++/6/complex:45,
                 from /usr/include/c++/6/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
                 from /in/foo.cc:1:
/usr/include/c++/6/istream:168:7: note: candidate: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>] <near match>
       operator>>(bool& __n)
       ^~~~~~~~
/usr/include/c++/6/istream:168:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:20:24: warning: the address of 'double y1(double)' will always evaluate as 'true' [-Waddress]
     while(cin >> x1 >> y1 >> x2 >> y2) merge(f(x1, y1),f(x2, y2));
                        ^~
/in/foo.cc:20:24: error: invalid initialization of non-const reference of type 'bool&' from an rvalue of type 'bool'
In file included from /usr/include/c++/6/sstream:38:0,
                 from /usr/include/c++/6/complex:45,
                 from /usr/include/c++/6/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
                 from /in/foo.cc:1:
/usr/include/c++/6/istream:172:7: note: candidate: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>] <near match>
       operator>>(short& __n);
       ^~~~~~~~
/usr/include/c++/6/istream:172:7: note:   conversion of argument 1 would be ill-formed