#!/usr/bin/perl

my @pasture;
my $animal;

    @pasture = qw(Cow Cow Horse Sheep Sheep Cow);
    foreach $animal (@pasture) {
      $animal->speak;
    }


{ package Cow;
	@ISA  = qw(Animal);
	sub sound { "moooo" }
}

{ package Horse;
	sub sound { "neigh" }
	sub speak {
		my $class = shift;
		print "a $class goes ", $class->sound, "!\n";
	}
}

{ package Sheep;
	sub sound { "baaaaaaaa" }
	sub speak {
		my $class = shift;
		print "a $class goes ", $class->sound, "!\n";
	}
}

    { package Animal;
      sub speak {
	my $class = shift;
	print "a $class goes ", $class->sound, "!\n"
      }
    }