View Compilation Error

0_0_38545819_4009.cpp: In function 'int main()':
0_0_38545819_4009.cpp:21:2: error: 'cin' was not declared in this scope
  cin >> x >> y;
  ^
0_0_38545819_4009.cpp:38:5: error: 'cout' was not declared in this scope
     cout << "OK" << endl;
     ^
0_0_38545819_4009.cpp:38:21: error: 'endl' was not declared in this scope
     cout << "OK" << endl;
                     ^
0_0_38545819_4009.cpp:42:5: error: 'cout' was not declared in this scope
     cout << "Sorry" << endl;
     ^
0_0_38545819_4009.cpp:42:24: error: 'endl' was not declared in this scope
     cout << "Sorry" << endl;
                        ^