/in/foo.cc: In function 'int main()':
/in/foo.cc:8:5: error: 'cin' was not declared in this scope
     cin >> m >> d;
     ^~~
/in/foo.cc:16:9: error: 'cout' was not declared in this scope
         cout << "Crazy Thursday V me 50!" << endl;
         ^~~~
/in/foo.cc:16:46: error: 'endl' was not declared in this scope
         cout << "Crazy Thursday V me 50!" << endl;
                                              ^~~~
/in/foo.cc:20:9: error: 'cout' was not declared in this scope
         cout << "o.O" << endl;
         ^~~~
/in/foo.cc:20:26: error: 'endl' was not declared in this scope
         cout << "o.O" << endl;
                          ^~~~
/in/foo.cc:10:9: warning: unused variable 'days_in_month' [-Wunused-variable]
     int days_in_month[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
         ^~~~~~~~~~~~~