/in/foo.cc: In function 'int main()':
/in/foo.cc:50:14: error: conflicting declaration 'Date d'
   50 |         Date d(y,m,d);
      |              ^
/in/foo.cc:47:17: note: previous declaration as 'int d'
   47 |         int y,m,d,num;
      |                 ^
/in/foo.cc:51:11: error: request for member 'Add' in 'd', which is of non-class type 'int'
   51 |         d.Add(num);
      |           ^~~
/in/foo.cc:52:11: error: request for member 'Output' in 'd', which is of non-class type 'int'
   52 |         d.Output();
      |           ^~~~~~