while (time) {
   $Seconds = substr(time,-3,1);
   if ($Seconds == 4&&$Factor != 1) {
      print "It begins.";
      $Factor = 1;
   } elsif ($Seconds == 5&&$Factor == 1) {
      print "It ends.";
      $Factor = 0;
   }
   $Input = <STDIN>;
   chomp($Input);
   if ($Input eq "time") {
      print time;
      print "\n";
   } elsif ($Input eq "quit") {
      exit;
   }
}