Collatz conjecture for Perl

script.pl

#!/usr/bin/perl
# This script finds the number of cycles necessary to get to 1 via the
# Collatz conjecture.
use strict;
use warnings;

unless (defined $ARGV[0]) {
	print("Supply the integer as the first argument.");
	exit;
}

my $i = $ARGV[0];
my $steps = 0;

while ($i != 1) {
	$steps++;

	# is even
	if ($i % 2 == 0) {
		$i = $i / 2;
	} else {
		# is odd
		$i = ($i * 3) + 1;
	}
}

print("Done. Took " . $steps . " to bring " . $ARGV[0] . " to 1.\n");