# code: http://golf.shinh.org/reveal.rb?Digit+depth/darrenks_1644422075&nbb
# target Nibbles version: 0.23
# commenter version: 0.1.2.181

! #(zip with):[chr] 
    =\ #(scanl):[int] 
        fstLine #(@):[chr] 
        \B A 
        fstInt #(_):int 
        \D C 
        + #(add):int 
            - #(subtract):int 
                % #(modulus):int 
                    + #(add):chr 
                        D #($):chr 
                        ~ #(auto = 1):auto 
                    3 #(integer):int 
                ~ #(auto = 1):auto 
            C #(@):int 
    \E 
    fstLine #(_):[chr] 
    ~ #(zipop: by):null 
    \G F 
    / #(foldr1):chr 
        : #(append):[chr] 
            \ #(char class):[chr] 
                F #(@):chr 
                D #(not.isDigit):null 
            #(implicit arg = G):int 
        #\I H 
        #(implicit arg = I):chr