%hash = (
          '1-1' => 80,
          '1-4' => 26,
          '4-4' => 3,
          '2-2' => 180,
          '2-4' => 72,
          '1-2' => 2196
        );
  $N =2;
  %hash = seq_score($N,%hash); 
  printhash(%hash);

#---sub-----
sub seq_score{

  use Tie::IxHash;
  tie my %spair, "Tie::IxHash"; #modified

  ($N,%spair) = @_;
  my %topN_pair = ();
  my %seq =();

  my $t = Tie::IxHash->new(%spair);  #set new class
  $t->Reorder( reverse $t->SortByValue()->Keys() );#desc sort by value
   %topN_pair = $t->Splice(0, $N);                   
   return %topN_pair;
}

sub printhash
{
	my %hash = @_;
	
	foreach my $key (sort{$hash{$b}<=>$hash{$a}} keys %hash )
	{   next if ($hash{$key} <=1);
	    print $key, ":", $hash{$key}, "\n"
	}				
}