answer.code: In function ‘__int128 unsigned receive(int, int, const string&)’:
answer.code:31:17: error: no matching function for call to ‘swap(const value_type&, const value_type&)’
   31 |             swap(msg[a],msg[i]);
      |             ~~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54,
                 from answer.code:1:
/usr/include/c++/11/sstream:1185:5: note: candidate: ‘template<class _CharT, class _Traits, class _Allocator> void std::__cxx11::swap(std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>&, std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>&)’
 1185 |     swap(basic_stringbuf<_CharT, _Traits, _Allocator>& __x,
      |     ^~~~
/usr/include/c++/11/sstream:1185:5: note:   template argument deduction/substitution failed:
answer.code:31:17: note:   mismatched types ‘std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>’ and ‘const value_type’ {aka ‘const char’}
   31 |             swap(msg[a],msg[i]);
      |             ~~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54,
                 from answer.code:1:
/usr/include/c++/11/sstream:1193:5: note: candidate: ‘template<class _CharT, class _Traits, class _Allocator> void std::__cxx11::swap(std::__cxx11::basic_istringstream<_CharT, _Traits, _Allocator>&, std::__cxx11::basic_istringstream<_CharT, _Traits, _Allocator>&)’
 1193 |     swap(basic_istringstream<_CharT, _Traits, _Allocator>& __x,
      |     ^~~~
/usr/include/c++/11/sstream:1193:5: note:   template argument deduction/substitution failed:
answer.code:31:17: note:   mismatched types ‘std::__cxx11::basic_istringstream<_CharT, _Traits, _Allocator>’ and ‘const value_type’ {aka ‘const char’}
   31 |             swap(msg[a],msg[i]);
      |             ~~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54,
                 from answer.code:1:
/usr/include/c++/11/sstream:1200:5: note: candidate: ‘template<class _CharT, class _Traits, class _Allocator> void std::__cxx11::swap(std::__cxx11::basic_ostringstream<_CharT, _Traits, _Allocator>&, std::__cxx11::basic_ostringstream<_CharT, _Traits, _Allocator>&)’
 1200 |     swap(basic_ostringstream<_CharT, _Traits, _Allocator>& __x,
      |     ^~~~
/usr/include/c++/11/sstream:1200:5: note:   template argument deduction/substitution failed:
answer.code:31:17: note:   mismatched types ‘std::__cxx11::basic_ostringstream<_CharT, _Traits, _Allocator>’ and ‘const value_type’ {aka ‘const char’}
   31 |             swap(msg[a],msg[i]);
      |             ~~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54,
                 from answer.code:1:
/usr/include/c++/11/sstream:1207:5: note: candidate: ‘template<class _CharT, class _Traits, class _Allocator> void std::__cxx11::swap(std::__cxx11::basic_stringstream<_CharT, _Traits, _Allocator>&, std::__cxx11::basic_stringstream<_CharT, _Traits, _Allocator>&)’
 1207 |     swap(basic_stringstream<_CharT, _Traits, _Allocator>& __x,
      |     ^~~~
/usr/include/c++/11/sstream:1207:5: note:   template argument deduction/substitution failed:
answer.code:31:17: note:   mismatched types ‘std::__cxx11::basic_stringstream<_CharT, _Traits, _Allocator>’ and ‘const value_type’ {aka ‘const char’}
   31 |             swap(msg[a],msg[i]);
      |             ~~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/11/regex:63,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:110,
                 from answer.code:1:
/usr/include/c++/11/bits/regex.h:872:5: note: candidate: ‘template<class _Ch_type, class _Rx_traits> void std::__cxx11::swap(std::__cxx11::basic_regex<_Ch_type, _Rx_traits>&, std::__cxx11::basic_regex<_Ch_type, _Rx_traits>&)’
  872 |     swap(basic_regex<_Ch_type, _Rx_traits>& __lhs,
      |     ^~~~
/usr/include/c++/11/bits/regex.h:872:5: note:   template argument deduction/substitution failed:
answer.code:31:17: note:   mismatched types ‘std::__cxx11::basic_regex<_Ch_type, _Rx_traits>’ and ‘const value_type’ {aka ‘const char’}
   31 |             swap(msg[a],msg[i]);
      |             ~~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/11/regex:63,
                 from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:110,
                 from answer.code:1:
/usr/include/c++/11/bits/regex.h:2165:5: note: candidate: ‘template<class _Bi_iter, class _Alloc> void std::__cxx11::swap(std::__cxx11::match_results<_BiIter, _Alloc>&, std::__cxx11::match_results<_BiIter, _All...