g=:4 :'I.0=x|(+/b*,"."0 a)+y*i.X' 3 :0;._2(1!:1)3 a=:4}.y p=:a i.'?' X=:10 wd({.":".>(X=#a){'X g p{b=:13$1 3';'11 g>:p[b=:>:i.X')(p+4)}y )