View Compilation Error

0_0_27443398_11878.cpp: In function 'int main()':
0_0_27443398_11878.cpp:17:35: error: 'scanf' was not declared in this scope
  while (scanf("%d %d %d", &A,&B,&n) && (A != 0 && B != 0 && n != 0))
                                   ^
0_0_27443398_11878.cpp:20:21: error: 'printf' was not declared in this scope
   printf("%d\n", ans);
                     ^