# code: http://golf.shinh.org/reveal.rb?Set+symmetric+difference/tails_1643205712&nbb
# target Nibbles version: 1.00
# commenter version: 0.1.2.181

* #(join):[[chr],[chr]] 
    " " #(string):[chr] 
    %~ #(split by):[[[chr]],[[chr]]] 
        `^ #(list xor):[[chr]] 
            % #(split (remove empties)):[[chr]] 
                fstLine #(@):[chr] 
                ~ #(auto = words):auto 
            \A 
            + #(concat):[chr] 
                allLines #(;_):[[chr]] 
        \B 
        , #(length):int 
            #(implicit arg = B):[chr]