# code: http://golf.shinh.org/reveal.rb?kaprekars+routine/tails_1766045584&nbb
# target Nibbles version: 0.23
# commenter version: 0.1.6.187

>> #(tail):[[chr]] 
    `. #(iterate while uniq):[[chr]] 
        fstLine #(@):[chr] 
        \A 
        & #(justify):[chr] 
            "0" #(string):[chr] 
            , #(length):int 
                A #($):[chr] 
            - #(subtract):int 
                `r #(read int):int 
                    \ #(reverse):[chr] 
                        ; #(save):[chr] 
                            `< #(sort):[chr] 
                                A #($):[chr] 
                        sets B 
                `r #(read int):int 
                    B #($):[chr]