# code: http://golf.shinh.org/reveal.rb?three+piece+puzzle/tails_1700550246&nbb
# target Nibbles version: 1.00
# commenter version: 0.1.2.181

+ #(concat):[chr] 
    + #(concat):[[chr]] 
        =~ #(group by (also sorts)):[[[chr]]] 
            % #(split (remove empties)):[[chr]] 
                @ #(= fstLine):[chr] 
                ~ #(auto = words):auto 
            / #(foldr1):int <--arg( A:[chr] ) 
                . #(map):[int] 
                    $ #(= A):[chr] 
                    , #(length):int <--arg( B:chr ) 
                        `% #(split list (keep empties)):[[chr]] 
                            ;$ #(= fstLine):[chr] 
                            $ #(= B):chr 
                - #(subtract):int <--arg( D:int C:int ) 
                    #(implicit arg = D):int 
                    #(implicit arg = C):int