first you are right.. i made the result manually.. that was a simple mistake.. :)

actually it is an hash tree.. but i dont want to deflect the problem with code snippets..

keys are strings never arrays
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i dont agree.. just take a look at Hash::Multikey or perldsc or maybe it is a nested structure like this:

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

my %hash;
$hash{'number'}{'even'} = [24, 44, 38, 36];
$hash{'number'}{'odd'} = [23, 43, 37, 35];

foreach my $i(keys %hash){
    print $i;
    foreach my $j(keys %{$hash{$i}}){
        print "\t".$j."\t";
        print join(" ",@{$hash{'number'}{$j}})."\n";
    }
}
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furthermore thats offtopic :)