#!/usr/bin/perl -w

#perl-5.22.3

use strict;

my $href = {
            cat => {milk => 1},
            dog => {bone => 1}
};

if (keys %{$href->{cow}}) {
    print "noop\n";
} else {
    if (exists $href->{cow}) {
        print "holy cow\n";
    } else {
        print "no cow\n";
    }
}