View Compilation Error

0_0_38249562_12893.cpp: In function 'int main()':
0_0_38249562_12893.cpp:7:25: error: 'scanf' was not declared in this scope
     while (scanf("%d",&n) && n != 0){
                         ^
0_0_38249562_12893.cpp:33:25: error: 'printf' was not declared in this scope
         printf("%d",cont);
                         ^