View Compilation Error

0_0_34197411_32309.cpp: In function 'int main()':
0_0_34197411_32309.cpp:30:22: error: 'a' was not declared in this scope
   scanf("%lld%lld", &a, &b);
                      ^
0_0_34197411_32309.cpp:30:26: error: 'b' was not declared in this scope
   scanf("%lld%lld", &a, &b);
                          ^