() ~ elves set

0 2244 {
    listen dup
    strmeasure 0 eq?
    choose
    { pop pop elves cons ~ elves set 0 true } ifyes
    { numberize add } ifno
} repeat

elves shatter depth sub1 { 
    2 pick 2 pick lt? 
    choose
    { pop exch pop true } ifyes
    { pop } ifno
} repeat

disp