There are piles of bananas and h hours before the guards return. At a chosen speed k bananas/hour, each hour Koko eats from a single pile: min(k, remaining) bananas (a pile takes ceil(pile / k) hours). Return the smallest integer k that lets her finish all piles within h hours. Input format Input is [piles, h] , e.g. [[3,6,7,11],8] .