View Compilation Error

0_0_21029924_14573.cpp: In function 'int main()':
0_0_21029924_14573.cpp:6:10: error: 'cin' was not declared in this scope
    while(cin >> a >> b)
          ^
0_0_21029924_14573.cpp:7:6: error: 'cout' was not declared in this scope
      cout << a + b << endl;
      ^
0_0_21029924_14573.cpp:7:23: error: 'endl' was not declared in this scope
      cout << a + b << endl;
                       ^