Mã chấm: 268765

Main.cc: In function ‘int main()’:
Main.cc:10:3: error: ‘cin’ was not declared in this scope
   cin >> A >> B >> X >> Y;
   ^~~
Main.cc:10:3: note: suggested alternative: ‘sin’
   cin >> A >> B >> X >> Y;
   ^~~
   sin
Main.cc:16:3: error: ‘cout’ was not declared in this scope
   cout << tong << endl;
   ^~~~
Main.cc:16:3: note: suggested alternative: ‘cosl’
   cout << tong << endl;
   ^~~~
   cosl
Main.cc:16:19: error: ‘endl’ was not declared in this scope
   cout << tong << endl;
                   ^~~~
Main.cc:16:19: note: suggested alternative: ‘ynl’
   cout << tong << endl;
                   ^~~~
                   ynl