第二题是巧克力吗？

import java.util.Scanner; /** public class Main4 {

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);

        int N = in.nextInt();

        int M = in.nextInt();

        int lo = 1, hi = M;

        while (lo + 1 < hi) {

            int mid = lo + (hi - lo) / 2;

            if (isScatisfy(mid, N, M)) {

                lo = mid;

            } else {

                hi = mid - 1;

            }

        }         if (isScatisfy(lo+1, N, M)) {

            System.out.println(lo + 1);

        } else {

            System.out.println(lo);

        }

    }



    public static boolean isScatisfy(int v, int N, int M) {

        int ans = v;

        for (int i = 1; i < N; i++) {

            if (v == 1) {

                ans += N - i;

                break;

            } else {

                ans += (v + 1) / 2;

                v = (v + 1) / 2;

            }

        }
        return ans <= M;
    }

}