#!/usr/bin/perl

# Monte Carlo approximation of PI. Slow!

use strict;
use warnings;

my $in    =  0;
my $count = @ARGV ? shift : 1000;

rand () ** 2 + rand () ** 2 < 1 && $in ++ for 1 .. $count;

printf "Pi equals %f\n", 4 * $in / $count;