#!/usr/bin/perl -w

%iptable = ();
if(open(IN,"cities.txt"))
{
        while(<IN>) {
                @tmp = split(/\t/);
                print $tmp[0];
                print $tmp[1];
                $iptable{$tmp[0]} = $tmp[1];
        }
}


foreach $key(sort {$iptable{$a} cmp $iptable{$b}} keys %iptable)
{
 print "$key :$iptable{$key}\n";
}