# code: http://golf.shinh.org/reveal.rb?number+stairs/tails_1723684389&nbb
# target Nibbles version: 0.21
# commenter version: 0.1.6.187

#(implicit map with implicit range):[[[int]]] 
    9 #(integer):int 
    \B A 
    : #(append):[[int]] 
        , #(range from 1):[int] 
            B #($):int 
        ~ #(auto = []):auto