View Compilation Error

0_0_20271039_24881.cpp: In function 'int main()':
0_0_20271039_24881.cpp:5:21: error: 'scanf' was not declared in this scope
  while(scanf("%d",&n)!=EOF)
                     ^
0_0_20271039_24881.cpp:5:24: error: 'EOF' was not declared in this scope
  while(scanf("%d",&n)!=EOF)
                        ^
0_0_20271039_24881.cpp:8:20: error: 'printf' was not declared in this scope
   printf("%d\n",sum);
                    ^