View Compilation Error

1_734_3658_27824.cpp: In function 'int main()':
1_734_3658_27824.cpp:10:18: error: 'scanf' was not declared in this scope
     scanf("%d",&t);
                  ^
1_734_3658_27824.cpp:47:44: error: 'printf' was not declared in this scope
         printf("Case #%d: %lld\n",cas,ans+1);
                                            ^