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

my @a=qw(las vegas every saturday night third is my element);
my $leng= @a;
my $i;

print "the index of  the array is $leng. \n";

for ($i=0; $i <= $leng; $i++) {
	if (($i+1)%3==0) {
		print "$a[$i] ";
	}
	
}