View Compilation Error

0_0_19179415_4973.cpp: In function 'int main()':
0_0_19179415_4973.cpp:5:21: error: 'scanf' was not declared in this scope
  while(scanf("%d",&n)!=EOF&&n)
                     ^
0_0_19179415_4973.cpp:5:24: error: 'EOF' was not declared in this scope
  while(scanf("%d",&n)!=EOF&&n)
                        ^
0_0_19179415_4973.cpp:11:13: error: 'sushu' was not declared in this scope
    p=sushu(m);
             ^
0_0_19179415_4973.cpp:16:24: error: 'printf' was not declared in this scope
     printf("%d\n",count);
                        ^