#! perl -sw
use strict;

{
	my $next=0;
	sub elements(\@$) {
		my ($ref, $count) = @_;
		my $max = $#$ref;
		$next=0, return if $next > $max;
		my $first = $next;
		my $last = $next+$count-1;
		$last = $max if $max < $last;
		$next += $count;
		@{$ref}[$first .. $last];
	}
}

my @letters = ('a'..'z');
while(my @els = elements(@letters, 5) ) {
	print "@els\n";
}
__END__
a b c d e
f g h i j
k l m n o
p q r s t
u v w x y
z