View Compilation Error

0_0_36192061_19496.cpp: In function 'int main()':
0_0_36192061_19496.cpp:12:11: error: 'cin' was not declared in this scope
  int tim; cin >> tim;
           ^
0_0_36192061_19496.cpp:31:3: error: 'cout' was not declared in this scope
   cout << ans << endl;
   ^
0_0_36192061_19496.cpp:31:18: error: 'endl' was not declared in this scope
   cout << ans << endl;
                  ^