Language: C++

#include <iostream>

int main () 
{
cin >> a;
cin >> b;

if (a < b) {
cout << ???a < b??? << endl;
} else if (a == b) {
cout << ??? a == b??? << endl;
} else if (a > b) {
cout << ??? a > b ??? << endl;
}

return 0;

}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:1: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 | cin >> a;
      | ^~~
      | std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:5:8: error: 'a' was not declared in this scope
    5 | cin >> a;
      |        ^
a.cc:6:8: error: 'b' was not declared in this scope
    6 | cin >> b;
      |        ^
a.cc:9:1: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 | cout << ???a < b??? << 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:9:9: error: expected primary-expression before '?' token
    9 | cout << ???a < b??? << endl;
      |         ^
a.cc:9:10: error: expected primary-expression before '?' token
    9 | cout << ???a < b??? << endl;
      |          ^
a.cc:9:11: error: expected primary-expression before '?' token
    9 | cout << ???a < b??? << endl;
      |           ^
a.cc:9:18: error: expected primary-expression before '?' token
    9 | cout << ???a < b??? << endl;
      |                  ^
a.cc:9:19: error: expected primary-expression before '?' token
    9 | cout << ???a < b??? << endl;
      |                   ^
a.cc:9:21: error: expected primary-expression before '<<' token
    9 | cout << ???a < b??? << endl;
      |                     ^~
a.cc:9:24: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    9 | cout << ???a < b??? << endl;
      |                        ^~~~
      |                        std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:9:28: error: expected ':' before ';' token
    9 | cout << ???a < b??? << endl;
      |                            ^
      |                            :
a.cc:9:28: error: expected primary-expression before ';' token
a.cc:9:28: error: expected ':' before ';' token
    9 | cout << ???a < b??? << endl;
      |                            ^
      |                            :
a.cc:9:28: error: expected primary-expression before ';' token
a.cc:9:28: error: expected ':' before ';' token
    9 | cout << ???a < b??? << endl;
      |                            ^
      |                            :
a.cc:9:28: error: expected primary-expression before ';' token
a.cc:9:28: error: expected ':' before ';' token
    9 | cout << ???a < b??? << endl;
      |                            ^
      |                            :
a.cc:9:28: error: expected primary-expression before ';' token
a.cc:9:28: error: expected ':' before ';' token
    9 | cout << ???a < b??? << endl;
      |                            ^
      |                            :
a.cc:9:28: error: expected primary-expression before ';' token
a.cc:9:28: error: expected ':' before ';' token
    9 | cout << ???a < b??? << endl;
      |                            ^
      |                            :
a.cc:9:28: error: expected primary-expression before ';' token
a.cc:11:1: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   11 | cout << ??? a == b??? << 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:11:9: error: expected primary-expression before '?' token
   11 | cout << ??? a == b??? << endl;
      |         ^
a.cc:11:10: error: expected primary-expression before '?' token
   11 | cout << ??? a == b??? << endl;
      |          ^
a.cc:11:11: error: expected primary-expression before '?' token
   11 | cout << ??? a == b??? << endl;
      |           ^
a.cc:11:20: error: expected primary-expression before '?' token
   11 | cout << ??? a == b??? << endl;
      |                    ^
a.cc:11:21: error: expected primary-expression before '?' token
   11 | cout << ??? a == b??? << endl;
      |                     ^
a.cc:11:23: error: expected primary-expression before '<<' token
   11 | cout << ??? a == b??? << endl;
      |                       ^~
a.cc:11:26: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   11 | cout << ??? a == b??? << endl;
      |                          ^~~~
      |                          std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:11:30: error: expected ':' before ';' token
   11 | cout << ??? a == b??? << endl;
      |                              ^
      |                              :
a.cc:11:30: error: expected primary-expression before ';' token
a.cc:11:30: error: expected ':' before ';' token
   11 | cout << ??? a == b??? << endl;
      |                              ^
      |                              :
a.cc:11:30: error: expected primary-expression before ';' token
a.cc:11:30: error: expected ':' before ';' token
   11 | cout << ??? a == b??? << endl;
      |                              ^
      |                              :
a.cc:11:30: error: expected primary-expression before ';' token
a.cc:11:30: error: expected ':' before ';' token
   11 | cout << ??? a == b??? << endl;
      |                              ^
      |                              :
a.cc:11:30: error: expected primary-expression before ';' token
a.cc:11:30: error: expected ':' before ';' token
   11 | cout << ??? a == b??? << endl;
      |                              ^
      |                              :
a.cc:11:30: error: expected primary-expression before ';' token
a.cc:11:30: error: expected ':' before ';' token
   11 | cout << ??? a == b??? << endl;
      |                              ^
      |                              :
a.cc:11:30: error: expected primary-expression before ';' token
a.cc:13:1: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   13 | cout << ??? a > b ??? << 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:13:9: error: expected primary-expression before '?' token
   13 | cout << ??? a > b ??? << endl;
      |         ^
a.cc:13:10: error: expected primary-expression before '?' token
   13 | cout << ??? a > b ??? << endl;
      |          ^
a.cc:13:11: error: expected primary-expression before '?' token
   13 | cout << ??? a > b ??? << endl;
      |           ^
a.cc:13:20: error: expected primary-expression before '?' token
   13 | cout << ??? a > b ??? << endl;
      |                    ^
a.cc:13:21: error: expected primary-expression before '?' token
   13 | cout << ??? a > b ??? << endl;
      |                     ^
a.cc:13:23: error: expected primary-expression before '<<' token
   13 | cout << ??? a > b ??? << endl;
      |                       ^~
a.cc:13:26: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   13 | cout << ??? a > b ??? << endl;
      |                          ^~~~
      |                          std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:13:30: error: expected ':' before ';' token
   13 | cout << ??? a > b ??? << endl;
      |                              ^
      |                              :
a.cc:13:30: error: expected primary-expression before ';' token
a.cc:13:30: error: expected ':' before ';' token
   13 | cout << ??? a > b ??? << endl;
      |                              ^
      |                              :
a.cc:13:30: error: expected primary-expression before ';' token
a.cc:13:30: error: expected ':' before ';' token
   13 | cout << ??? a > b ??? << endl;
      |                              ^
      |                              :
a.cc:13:30: error: expected primary-expression before ';' token
a.cc:13:30: error: expected ':' before ';' token
   13 | cout << ??? a > b ??? << endl;
      |                              ^
      |                              :
a.cc:13:30: error: expected primary-expression before ';' token
a.cc:13:30: error: expected ':' before ';' token
   13 | cout << ??? a > b ??? << endl;
      |                              ^
      |                              :
a.cc:13:30: error: expected primary-expression before ';' token
a.cc:13:30: error: expected ':' before ';' token
   13 | cout << ??? a > b ??? << endl;
      |                              ^
      |                              :
a.cc:13:30: error: expected primary-expression before ';' token