Language: C++

#include <iostream>
#include <set>
#include <string>
using namespace std;

int main(){
int n;
cin >> n;
set<string> ss;
while(n--){
string s;
cin >> s;
ss.insert(s);
}

cout << ss.begin() << endl;
return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:16:6: error: no match for 'operator<<' (operand types are 'std::ostream' {aka 'std::basic_ostream<char>'} and 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'})
   16 | cout << ss.begin() << endl;
      | ~~~~ ^~ ~~~~~~~~~~
      | |               |
      | |               std::set<std::__cxx11::basic_string<char> >::iterator {aka std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator}
      | std::ostream {aka std::basic_ostream<char>}
In file included from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/ostream:116:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(__ostream_type& (*)(__ostream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  116 |       operator<<(__ostream_type& (*__pf)(__ostream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:116:36: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'std::basic_ostream<char>::__ostream_type& (*)(std::basic_ostream<char>::__ostream_type&)' {aka 'std::basic_ostream<char>& (*)(std::basic_ostream<char>&)'}
  116 |       operator<<(__ostream_type& (*__pf)(__ostream_type&))
      |                  ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:125:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>; __ios_type = std::basic_ios<char>]'
  125 |       operator<<(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:125:32: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'std::basic_ostream<char>::__ios_type& (*)(std::basic_ostream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'}
  125 |       operator<<(__ios_type& (*__pf)(__ios_type&))
      |                  ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:135:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  135 |       operator<<(ios_base& (*__pf) (ios_base&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:135:30: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'std::ios_base& (*)(std::ios_base&)'
  135 |       operator<<(ios_base& (*__pf) (ios_base&))
      |                  ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:174:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  174 |       operator<<(long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:174:23: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'long int'
  174 |       operator<<(long __n)
      |                  ~~~~~^~~
/usr/include/c++/14/ostream:178:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  178 |       operator<<(unsigned long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:178:32: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'long unsigned int'
  178 |       operator<<(unsigned long __n)
      |                  ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/ostream:182:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  182 |       operator<<(bool __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:182:23: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'bool'
  182 |       operator<<(bool __n)
      |                  ~~~~~^~~
In file included from /usr/include/c++/14/ostream:1022:
/usr/include/c++/14/bits/ostream.tcc:96:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char; _Traits = std::char_traits<char>]'
   96 |     basic_ostream<_CharT, _Traits>::
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/ostream.tcc:97:22: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'short int'
   97 |     operator<<(short __n)
      |                ~~~~~~^~~
/usr/include/c++/14/ostream:189:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  189 |       operator<<(unsigned short __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:189:33: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'short unsigned int'
  189 |       operator<<(unsigned short __n)
      |                  ~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/ostream.tcc:110:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char; _Traits = std::char_traits<char>]'
  110 |     basic_ostream<_CharT, _Traits>::
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/ostream.tcc:111:20: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'int'
  111 |     operator<<(int __n)
      |                ~~~~^~~
/usr/include/c++/14/ostream:200:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  200 |       operator<<(unsigned int __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:200:31: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>, std::_Identity<std::__cxx11::basic_string<char> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::__cxx11::basic_string<char> > >::const_iterator'} to 'unsigned int'
  200 |       operator<<(unsigned int __n)
      |                  ~~~~~~~~~~~~~^~~
/usr/include/c++/14/ostream:211:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  211 |       operator<<(long long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:211:28: note:   no known conversion for argument 1 from 'std::set<std::__cxx11::basic_string<char> >: