View Compilation Error

0_0_29377232_20805.cpp: In function 'int main()':
0_0_29377232_20805.cpp:6:18: error: 'a' was not declared in this scope
     while(cin >> a >> b) cout << a+b << endl;
                  ^
0_0_29377232_20805.cpp:6:23: error: 'b' was not declared in this scope
     while(cin >> a >> b) cout << a+b << endl;
                       ^