l20.pl

   1 #!/usr/bin/perl
   2 use warnings;
   3 use strict;
   4
   5 use constant
   6   {
   7     SPEED_OF_LIGHT => 299_792_458,
   8     AVERAGE_DISTANCE_TO_MOON => 384400000,
   9   };
  10
  11 print "Свет от земли до луны дойдет за " .
  12 AVERAGE_DISTANCE_TO_MOON/SPEED_OF_LIGHT . "сек\n";