$.=", E-I-E-I-O.
";$t=here;for$b(@B=qw(moo baa quack oink)){$@=&W." $b-$b ";print$_&&$/,$0="Old MacDonald had a farm$.","And on his farm he had a ",qw(cow pig duck sheep)[$_],"$.With $@$t, and $@t$t.
";"@B[-$_,~$_]"=~$",$@=&W.$".$`,print"\u$t $@, t$t $@, everyw$t $@-$`.
",$_?"A $'-$' $t, and a $'-$' t$t.
":$0for$_--..0}sub W{/3/?an:a}