#!/usr/bin/perl
use strict;
use warnings;

my $VAR1 = {
          '212' => {
                     '42' => 6,
                     '49' => 6,
                     '41' => 1
                   },
          '282' => {
                     '38' => 4,
                     '39' => 1,
                     '37' => 2
                   }
        };

my %reg = %{$VAR1};
my $c = 1;
# sort by the item with the most sub-keys first
# if there is a tie sort by sub-keys 
foreach my $item (sort { scalar keys (%{$reg{$b}})<=>scalar keys (%{$reg{$a}}) 
                                  ||
                                $a<=>$b   } keys %reg){                                    
    foreach my $case (sort {$reg{$item}{$a}<=>$reg{$item}{$b}} keys %{$reg{$item}}){
        print "$c = $item:$case\n";
        $c++;
    }
}