/in/foo.cc: In function 'int main()':
/in/foo.cc:84:21: warning: variable 'sum' set but not used [-Wunused-but-set-variable]
  int year,month,day,sum;
                     ^~~
/in/foo.cc:99:25: warning: 'day' may be used uninitialized in this function [-Wmaybe-uninitialized]
   printmonth(day,m,year);
                         ^