Language: C++

#include<iostream>
using naamespace std;
int main(){
    int m,f,r;
    while(m!=-1 || f!=-1 || r!=-1){
        cin >> m >> f >> r;
        if(m!=-1 && f!=-1){
            if(m+f>=80) cout<<"A"<<endl;
            else if(m+f>=65 && m+f<80) cout<<"B"<<endl;
            else if(m+f<=50 && m+f>65) cout<<"C"<<endl;
            else if(m+f<=35 && m+f>50){
                if(r>=50) cout<<"C"<<endl;
                else cout<<"D"<<endl;
            }
            else cout<<"E"<<endl;
        }
        else break;
    }
    return 0;
}


Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'naamespace'
    2 | using naamespace std;
      |       ^~~~~~~~~~
a.cc: In function 'int main()':
a.cc:6:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |         cin >> m >> f >> r;
      |         ^~~
      |         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:8:25: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    8 |             if(m+f>=80) cout<<"A"<<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:8:36: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    8 |             if(m+f>=80) cout<<"A"<<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:9:40: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 |             else if(m+f>=65 && m+f<80) cout<<"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:9:51: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    9 |             else if(m+f>=65 && m+f<80) cout<<"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:10:40: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   10 |             else if(m+f<=50 && m+f>65) cout<<"C"<<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:10:51: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   10 |             else if(m+f<=50 && m+f>65) cout<<"C"<<endl;
      |                                                   ^~~~
      |                                                   std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:12:27: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   12 |                 if(r>=50) cout<<"C"<<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:12:38: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   12 |                 if(r>=50) cout<<"C"<<endl;
      |                                      ^~~~
      |                                      std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:13:22: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   13 |                 else cout<<"D"<<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:13:33: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   13 |                 else cout<<"D"<<endl;
      |                                 ^~~~
      |                                 std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:15:18: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   15 |             else cout<<"E"<<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:15:29: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   15 |             else cout<<"E"<<endl;
      |                             ^~~~
      |                             std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~