#!/usr/bin/perl -w


use strict;


my %hash = (

'c' =>
{ 'e' => '54.9503577512828',
           '21' => '40.4544882398113',
           '7' => '13.665886711539',
           '17' => '26.3268082750993',
           '2' => '16.4348644122811',
           '22' => '35.2357587506792',
           '1' => '29.5471128362965',
           '18' => '28.8861232027377',
           '23' => '19.3437720284897',

         },
'd'  =>
        {

           '11' => '26.7647206436788',
           '21' => '19.4128184125387',
           '7' => '6.89345884629317',
           '17' => '12.7682648883531',
           '2' => '8.44015343941174',
           '22' => '16.9085166076037',
           '1' => '15.1739716114483',
           '18' => '13.9203445318945',

         },
'b' =>
        {
           '11' => '11.5303855045498',
           '21' => '9.28718107649433',
           '7' => '2.50040155572952',
           '17' => '5.93010343000324',
           '2' => '2.86098737229312',

         }

);

foreach my $k1 (sort keys %hash){
   print "\n-> $k1\n";
   my $count = 0;
   foreach my $k2 (sort {$hash{$k1}->{$b} <=> $hash{$k1}->{$a} } keys %{$hash{$k1}} ){
        print "--> $k2: $hash{$k1}->{$k2}\n";
        last if $count++ > 0;
   }
}