View Compilation Error

0_0_15141992_6816.cpp: In function 'int main()':
0_0_15141992_6816.cpp:4:18: error: 'scanf' was not declared in this scope
     scanf("%d",&t);
                  ^
0_0_15141992_6816.cpp:10:46: error: 'printf' was not declared in this scope
             if(d==21) printf("It's today!!\n");
                                              ^
0_0_15141992_6816.cpp:11:45: error: 'printf' was not declared in this scope
             else if(d<21) printf("%d\n",21-d);
                                             ^
0_0_15141992_6816.cpp:12:56: error: 'printf' was not declared in this scope
             else printf("What a pity, it has passed!\n");
                                                        ^
0_0_15141992_6816.cpp:14:61: error: 'printf' was not declared in this scope
         else if(m>10) printf("What a pity, it has passed!\n");
                                                             ^
0_0_15141992_6816.cpp:26:28: error: 'printf' was not declared in this scope
             printf("%d\n",s);
                            ^