View Compilation Error

0_0_37153353_5568.cpp: In function 'int main()':
0_0_37153353_5568.cpp:4:21: error: 'scanf' was not declared in this scope
  while(scanf("%d",&n))
                     ^
0_0_37153353_5568.cpp:8:21: error: 'EOF' was not declared in this scope
     scanf("%d",&a)!=EOF;
                     ^
0_0_37153353_5568.cpp:14:22: error: 'printf' was not declared in this scope
     printf("%d\n",sum);
                      ^