View Compilation Error

0_0_21379953_13272.cpp: In function 'int main()':
0_0_21379953_13272.cpp:4:24: error: 'scanf' was not declared in this scope
     while(scanf("%d",&t)&&t!=0)  
                        ^
0_0_21379953_13272.cpp:13:26: error: 'printf' was not declared in this scope
         printf("%d\n",sum);  
                          ^