/in/foo.cc: In function 'int main()':
/in/foo.cc:7:14: warning: unused variable 'month' [-Wunused-variable]
     int year,month,day;
              ^~~~~
/in/foo.cc:7:20: warning: unused variable 'day' [-Wunused-variable]
     int year,month,day;
                    ^~~
/in/foo.cc:8:15: warning: unused variable 'month2' [-Wunused-variable]
     int year2,month2,day2;
               ^~~~~~
/in/foo.cc:8:22: warning: unused variable 'day2' [-Wunused-variable]
     int year2,month2,day2;
                      ^~~~