/in/foo.cc: In function 'int main()':
/in/foo.cc:24:7: error: reference to 'begin' is ambiguous
  cin>>begin;
       ^~~~~
/in/foo.cc:5:5: note: candidates are: int begin
 int begin,end,now;
     ^~~~~
In file included from /usr/include/c++/6/string:51:0,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/range_access.h:87:5: note:                 template<class _Tp, long unsigned int _Nm> _Tp* std::begin(_Tp (&)[_Nm])
     begin(_Tp (&__arr)[_Nm])
     ^~~~~
/usr/include/c++/6/bits/range_access.h:58:5: note:                 template<class _Container> decltype (__cont.begin()) std::begin(const _Container&)
     begin(const _Container& __cont) -> decltype(__cont.begin())
     ^~~~~
/usr/include/c++/6/bits/range_access.h:48:5: note:                 template<class _Container> decltype (__cont.begin()) std::begin(_Container&)
     begin(_Container& __cont) -> decltype(__cont.begin())
     ^~~~~
In file included from /usr/include/c++/6/bits/range_access.h:36:0,
                 from /usr/include/c++/6/string:51,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/initializer_list:89:5: note:                 template<class _Tp> constexpr const _Tp* std::begin(std::initializer_list<_Tp>)
     begin(initializer_list<_Tp> __ils) noexcept
     ^~~~~
/in/foo.cc:25:7: error: reference to 'end' is ambiguous
  cin>>end;
       ^~~
/in/foo.cc:5:11: note: candidates are: int end
 int begin,end,now;
           ^~~
In file included from /usr/include/c++/6/string:51:0,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/range_access.h:97:5: note:                 template<class _Tp, long unsigned int _Nm> _Tp* std::end(_Tp (&)[_Nm])
     end(_Tp (&__arr)[_Nm])
     ^~~
/usr/include/c++/6/bits/range_access.h:78:5: note:                 template<class _Container> decltype (__cont.end()) std::end(const _Container&)
     end(const _Container& __cont) -> decltype(__cont.end())
     ^~~
/usr/include/c++/6/bits/range_access.h:68:5: note:                 template<class _Container> decltype (__cont.end()) std::end(_Container&)
     end(_Container& __cont) -> decltype(__cont.end())
     ^~~
In file included from /usr/include/c++/6/bits/range_access.h:36:0,
                 from /usr/include/c++/6/string:51,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/initializer_list:99:5: note:                 template<class _Tp> constexpr const _Tp* std::end(std::initializer_list<_Tp>)
     end(initializer_list<_Tp> __ils) noexcept
     ^~~
/in/foo.cc:26:6: error: reference to 'begin' is ambiguous
  now=begin;
      ^~~~~
/in/foo.cc:5:5: note: candidates are: int begin
 int begin,end,now;
     ^~~~~
In file included from /usr/include/c++/6/string:51:0,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/range_access.h:87:5: note:                 template<class _Tp, long unsigned int _Nm> _Tp* std::begin(_Tp (&)[_Nm])
     begin(_Tp (&__arr)[_Nm])
     ^~~~~
/usr/include/c++/6/bits/range_access.h:58:5: note:                 template<class _Container> decltype (__cont.begin()) std::begin(const _Container&)
     begin(const _Container& __cont) -> decltype(__cont.begin())
     ^~~~~
/usr/include/c++/6/bits/range_access.h:48:5: note:                 template<class _Container> decltype (__cont.begin()) std::begin(_Container&)
     begin(_Container& __cont) -> decltype(__cont.begin())
     ^~~~~
In file included from /usr/include/c++/6/bits/range_access.h:36:0,
                 from /usr/include/c++/6/string:51,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/initializer_list:89:5: note:                 template<class _Tp> constexpr const _Tp* std::begin(std::initializer_list<_Tp>)
     begin(initializer_list<_Tp> __ils) noexcept
     ^~~~~
/in/foo.cc:27:13: error: reference to 'end' is ambiguous
  while(now<=end)
             ^~~
/in/foo.cc:5:11: note: candidates are: int end
 int begin,end,now;
           ^~~
In file included from /usr/include/c++/6/string:51:0,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/range_access.h:97:5: note:                 template<class _Tp, long unsigned int _Nm> _Tp* std::end(_Tp (&)[_Nm])
     end(_Tp (&__arr)[_Nm])
     ^~~
/usr/include/c++/6/bits/range_access.h:78:5: note:                 template<class _Container> decltype (__cont.end()) std::end(const _Container&)
     end(const _Container& __cont) -> decltype(__cont.end())
     ^~~
/usr/include/c++/6/bits/range_access.h:68:5: note:                 template<class _Container> decltype (__cont.end()) std::end(_Container&)
     end(_Container& __cont) -> decltype(__cont.end())
     ^~~
In file included from /usr/include/c++/6/bits/range_access.h:36:0,
                 from /usr/include/c++/6/string:51,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/initializer_list:99:5: note:                 template<class _Tp> constexpr const _Tp* std::end(std::initializer_list<_Tp>)
     end(initializer_list<_Tp> __ils) noexcept
     ^~~
/in/foo.cc:50:11: error: reference to 'end' is ambiguous
   if(now==end) break;
           ^~~
/in/foo.cc:5:11: note: candidates are: int end
 int begin,end,now;
           ^~~
In file included from /usr/include/c++/6/string:51:0,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/range_access.h:97:5: note:                 template<class _Tp, long unsigned int _Nm> _Tp* std::end(_Tp (&)[_Nm])
     end(_Tp (&__arr)[_Nm])
     ^~~
/usr/include/c++/6/bits/range_access.h:78:5: note:                 template<class _Container> decltype (__cont.end()) std::end(const _Container&)
     end(const _Container& __cont) -> decltype(__cont.end())
     ^~~
/usr/include/c++/6/bits/range_access.h:68:5: note: