#!/usr/bin/perl -w
use strict;
use Data::Dumper;


my %HoH  = (
              'pk1' => {
                          'sk1' => [
                                     'val1',
                                     'val2'
                                   ],
                          'sk2' => {
                                      'tk1' => 'val1 val2 ',
                                      'tk2' => 'val9,val7'
                                   },
                           'sk3' => 'val10 val11',
                            'sk4' => 21
                        },
 
          'pk2' => {},

          'pk3' => {
                          'sk1' => [
                                     'val1',
                                     'val2'
                                   ],
                          'sk2' => {
                                      'tk1' => 'val1 val2 ',
                                      'tk2' => 'val9,val7'
                                   },
                           'sk3' => 'val2 val3',
                            'sk4' => 30
                        },
         
        ); 




foreach my $k ( keys %{HoH} ) 
{

    unless ( $HoH{$k} and values %{$HoH{$k}} ) 
    {
       delete $HoH{$k};
    }
    
}


       my @best_inst; #AoA
       my @best_key = sort {  $HoH{$b}->{'sk4'} <=>  $HoH{$a}->{'sk4'} } keys %HoH; 
       #print Dumper \@best_key;
       push (@best_inst,    $HoH{$best_key[0]}->{'sk4'},
                            $HoH{$best_key[0]}->{'sk1'},
                            $HoH{$best_key[0]}->{'sk2'},
                            $HoH{$best_key[0]}->{'sk3'} );


print Dumper \@best_inst;


##</code><code>##

$VAR1 = [
          30,
          [
            'val1',
            'val2'
          ],
          {
            'tk2' => 'val9,val7',
            'tk1' => 'val1 val2 '
          },
          'val2 val3'
        ];