View Compilation Error

0_0_22206996_3570.cpp: In function 'int main()':
0_0_22206996_3570.cpp:8:38: error: 'scanf' was not declared in this scope
     while((scanf("%d %d %ld",&a,&b,&n)==3)){
                                      ^
0_0_22206996_3570.cpp:15:27: error: 'printf' was not declared in this scope
         printf("%ld\n",mod);
                           ^