View Compilation Error

0_0_24116900_21871.cpp: In function 'int main()':
0_0_24116900_21871.cpp:4:5: error: 'cin' was not declared in this scope
     cin >> a >> b;
     ^
0_0_24116900_21871.cpp:5:5: error: 'cout' was not declared in this scope
     cout << a+b << endl;
     ^
0_0_24116900_21871.cpp:5:20: error: 'endl' was not declared in this scope
     cout << a+b << endl;
                    ^