View Compilation Error

0_0_24946910_4765.cpp: In function 'int main()':
0_0_24946910_4765.cpp:5:29: error: 'a' was not declared in this scope
     while (~scanf("%d %d", &a, &b)) {
                             ^
0_0_24946910_4765.cpp:5:33: error: 'b' was not declared in this scope
     while (~scanf("%d %d", &a, &b)) {
                                 ^