#!/usr/bin/perl -w

use strict;

my &hash;
while (<DATA>)
{
    $hash{$first} = $second; # only grabs the last value
}

while ((my $key, my $value) = each %construct) {
    print "The $key is: $value \n";
}

_DATA_
5	25
6	27
5	24
5	23
6	29	
6	30
4	22
5	25
6	27
4	22
4	21

##</code><code>##

The Key is: 5 
		25
		24
		23
		
The Key is: 6
		27
		29
		30
The Key is: 4
		22
		21