#!/usr/bin/perl -w
use strict;

my $cycle = initToggle( 3 );

for ( 1 .. 24 ) {
    print "$_\t" . &$cycle . "\n";
}

sub initToggle {
    my $limit = shift;
    my $count = 0;
    my $bit   = 0;
    unless ( $limit > 0 ) { die "initToggle() requires a positive argument\n" };

    return sub {
        $bit ^= 1 if $count++ % $limit == 0;
        return $bit;
    }
}