use integer;

print("month was new new\n");
print("----- --- --- ---\n");

foreach (0..23) {
   my $month = ($_ + 10) % 12;

   printf("%-5d %-3d %-3d %-3d\n",
      $_,
      -$month/10,
      -$month/10 + $_/12,
      ($_+10)/12-1
   );
}