View Compilation Error

0_0_35314380_4503.cpp: In function 'int main()':
0_0_35314380_4503.cpp:7:25: error: 'scanf' was not declared in this scope
     while(~scanf("%d",&n))
                         ^
0_0_35314380_4503.cpp:15:26: error: 'printf' was not declared in this scope
         printf("%d\n",ans);
                          ^