View Compilation Error

0_0_38225350_10311.cpp: In function 'int main()':
0_0_38225350_10311.cpp:6:19: error: 'a' was not declared in this scope
     while (cin >> a >> b) cout << a + b << endl;
                   ^
0_0_38225350_10311.cpp:6:24: error: 'b' was not declared in this scope
     while (cin >> a >> b) cout << a + b << endl;
                        ^