Language: C++

#include <bits/stdc++.h> using namespace std;
#define rep(i, n) for(int i=0;i<(int)(n);i++)
#define all(x)    (x).begin(),(x).end()
typedef long long ll;
const int MOD = (int)1e9 + 7;

int main(){
  int n;
  cin >> n;
  if(n < 1200) cout << "ABC" << endl;
  else if(n < 2800) cout << "ARC" << endl;
  else cout << "AGC" << endl;
}



Compiler output:
a.cc:1:26: warning: extra tokens at end of #include directive
    1 | #include <bits/stdc++.h> using namespace std;
      |                          ^~~~~
a.cc: In function 'int main()':
a.cc:9:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    9 |   cin >> n;
      |   ^~~
      |   std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 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:10:16: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   10 |   if(n < 1200) cout << "ABC" << 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:10:33: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   10 |   if(n < 1200) cout << "ABC" << endl;
      |                                 ^~~~
      |                                 std::endl
In file included from /usr/include/c++/14/istream:41,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:11:21: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   11 |   else if(n < 2800) cout << "ARC" << 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:11:38: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   11 |   else if(n < 2800) cout << "ARC" << endl;
      |                                      ^~~~
      |                                      std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:12:8: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   12 |   else cout << "AGC" << 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:12:25: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   12 |   else cout << "AGC" << endl;
      |                         ^~~~
      |                         std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~