View Compilation Error

0_0_14189381_3772.cpp: In function 'int main()':
0_0_14189381_3772.cpp:78:3: error: '__int64_t' was not declared in this scope
   __int64_t a,b;
   ^
0_0_14189381_3772.cpp:83:23: error: 'a' was not declared in this scope
     scanf("%lld%lld",&a,&b);
                       ^
0_0_14189381_3772.cpp:83:26: error: 'b' was not declared in this scope
     scanf("%lld%lld",&a,&b);
                          ^