Um, bug. I was too glib.

But that makes getting a strict version with a count of 84 a point of honour, right? :-)

sub p{
my@m=1;for my $p(@_){my@a;map{my$j=my$i=$_;$a[$j++]+=$_*$m[$i]for@$p}0
+..@m;@m=@a}\@m
}
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