#! /usr/bin/perl
use strict;
my $limit = $ARGV[0] || 10;

my $result = "jeg er glad.";
while( my $head = &swap ) {
    $result =  $head. " er glad " . $result;
}
print $result, "\n";

BEGIN {
    my @oss = qw( jeg du );
    my ( $index, $count );
    sub swap{
	( $limit > $count++ ) ?
               return $oss[ $index = not $index ] : return;
    }
}