View Compilation Error

0_0_32327082_16789.cpp: In function 'int main()':
0_0_32327082_16789.cpp:25:29: error: 'scanf' was not declared in this scope
  while(scanf("%d %d", &n, &m) == 2){
                             ^
0_0_32327082_16789.cpp:39:21: error: 'printf' was not declared in this scope
   printf("%d\n", ans);
                     ^