use strict;
use warnings;

sub trial($)
 {
 my $result;
 foreach (1..shift) {
    $result= $_  if rand($_) < 1;
    }
 return $result;
 }

############

my $trials= shift || 1000;
my $size= shift || 20;
my %results;

for (1..$trials) {
   ++$results{trial($size)};
   }

# show the results
for (1..$size) {
   printf "%5d: %5d\n", $_, ($results{$_} || 0);
   }