sub addtwo {

    my $params = shift;
	
    my $s = $params->{structure};
    
    # 
    if (ref($s) eq "LIST") {
         $c = 0;
        foreach $e (@{$s}) {
        	push @$s, addtwo({ structures => $e });
            #$s->[$c] = addtwo({ structure => $e });
            $c++;
        }

    # 
    } elsif (ref($s) eq "HASH") {

        if (scalar keys %{$s} == 0) {
            return undef;
        } else {
            foreach my $e (values %{$s}) {
            
                $s->{$e} = addtwo({ structure => $s->{$e} });
            }
      }
    
    } else {
        $s = 1;
    }

    return $c;

}

print addtwo([ { a => 1, b => 2, c => 3  }, { d => 4, e => 5 }, [ 6, 7, 8 ], 9, 10, 11, [ 12, 13, 14 ] ]);