View Compilation Error

0_0_25509839_28789.cpp: In function 'int main()':
0_0_25509839_28789.cpp:40:26: error: 'scanf' was not declared in this scope
     while (scanf("%d", &n), n)
                          ^
0_0_25509839_28789.cpp:49:29: error: 'printf' was not declared in this scope
         printf("%d\n", total);
                             ^