#!/usr/local/bin/perl -w

use strict;

my %numbers = ( '210' => 'rg1000',
                '212' => 'rg1000',
                '214' => 'rg1000',
                '215' => 'rg1000',
                '218' => 'rg1003',
                '221' => 'rg1000',
                '222' => 'rg1003',
                '223' => 'rg1003',
                '224' => 'rg1003' );

# if the first 2 digit match and point to the same rg then print only the first two digits with the rg
foreach my $item (keys %numbers) {
        print "$item\n";
}

#desired output
# 21 => rg1000
# 218 => rg1003
# 22 => rg1003
# 221 => rg1000