View Compilation Error

0_0_31228811_2692.cpp: In function 'int main()':
0_0_31228811_2692.cpp:4:32: error: 'scanf' was not declared in this scope
           while((~scanf("%d",&a)))
                                ^
0_0_31228811_2692.cpp:12:21: error: 'printf' was not declared in this scope
      printf("%d\n",c);
                     ^