p6.p6

my %words is Set = lines;

sub make-LDWL(\word, @prev is copy = []) {
    make-LDWL $_, take [|@prev, $_] for %words{word.comb.combinations(word.chars-1)».join}:k
}

my @longest;
for sort keys %words {
    my $cur := ([$_], |gather make-LDWL $_).sort(-*).head;
    say "One of longest chains for `$_` is $cur.join(' ▶ ')";
    @longest = $cur if $cur > @longest;
}
say @longest;