#!/usr/bin/perl

use strict;
use warnings;

my $number = 1;
my $limit = 20;

my @list_of_nums;

while ($number < $limit) {
  push @list_of_nums, $number;
  $number = $number + $list_of_nums[-2];
}

foreach my $item (@list_of_nums) {
  if (odd($item) eq 'Odd') {
    print "$item is Odd\n";
  }

  else {
    print "$item is Even\n";
  }
  
}


sub even {
  my $num = shift @_;

  if ($num == 1)
    {
      return 'Even';
    }

  else
    {
      return odd(--$num);
    }
}

sub odd {
  my $num = shift @_;

  if ($num == 1)
    {
      return 'Odd';
    }

  else {
    return even(--$num);
  }
}