#!/usr/bin/perl

use strict;
use warnings;

my %sorthash;

$sorthash{10}{20} = 3;
$sorthash{10}{40} = 1;
$sorthash{40}{50} = 4;
$sorthash{20}{30} = 2;

print 
  map { "keys: $_->[0]\t$_->[1]\tvalues: $sorthash{$_->[0]}{$_->[1]}\n" }
  sort { $a->[1] <=> $b->[1] }
  map { my $key=$_; map { [$key, $_] } keys %{$sorthash{$key}} }
  keys %sorthash;

__END__
keys: 10	20	values: 3
keys: 20	30	values: 2
keys: 10	40	values: 1
keys: 40	50	values: 4