# code: http://golf.shinh.org/reveal.rb?Missing+Digit/tails_1644381918&nbb
# target Nibbles version: 0.23
# commenter version: 0.1.2.181

/ #(foldr):int 
    fstLine #(@):[chr] 
    \B A 
    477 #(integer):int 
    \D C 
    - #(subtract):chr 
        C #(@):int 
        #(implicit arg = D):chr