Language: C++

#include <iostream>
#include <string>

int main() {
  int n,total;
  bool p,w,g,y;
  string s;
  cin >> n;
  for (int i=0; i<n; i++){
    cin >> s[i];
  }
  for(int i=0; i<n; i++){
    if (s[i] == 'P') p=true;
    if (s[i] == 'W') w=true;
    if (s[i] == 'G') g=true;
    if (s[i] == 'Y') y=true;
  }
  
  if (total==3) cout << "Three" << endl;
    else cout << "Four" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:3: error: 'string' was not declared in this scope
    7 |   string s;
      |   ^~~~~~
a.cc:7:3: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:8:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    8 |   cin >> n;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:10:12: error: 's' was not declared in this scope
   10 |     cin >> s[i];
      |            ^
a.cc:13:9: error: 's' was not declared in this scope
   13 |     if (s[i] == 'P') p=true;
      |         ^
a.cc:14:9: error: 's' was not declared in this scope
   14 |     if (s[i] == 'W') w=true;
      |         ^
a.cc:15:9: error: 's' was not declared in this scope
   15 |     if (s[i] == 'G') g=true;
      |         ^
a.cc:16:9: error: 's' was not declared in this scope
   16 |     if (s[i] == 'Y') y=true;
      |         ^
a.cc:19:17: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   19 |   if (total==3) cout << "Three" << endl;
      |                 ^~~~
      |                 std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:19:36: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   19 |   if (total==3) cout << "Three" << endl;
      |                                    ^~~~
      |                                    std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:20:10: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   20 |     else cout << "Four" << endl;
      |          ^~~~
      |          std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:20:28: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   20 |     else cout << "Four" << endl;
      |                            ^~~~
      |                            std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~