Okabe Super Hacker Daru stack remove box there n box number 1 n Initially box stackOkabe control freak give Daru 2n command n add box stack n remove box stack throw trash Okabe want Daru throw away box order 1 n of course mean impossible Daru perform Okabes remove command require box stackthat Daru decide wait Okabe look away reorder box stack way want he point time Okabes command can not add remove box itTell Daru minimum number time need reorder box successfully complete Okabes command it guarantee box add require remove