Problem:
Score : 200 points

Problem Statement

Takahashi's house has only one socket.

Takahashi wants to extend it with some number of power strips, each with A sockets, into B or more empty sockets.

One power strip with A sockets can extend one empty socket into A empty sockets.

Find the minimum number of power strips required.

Constraints

All values in input are integers.

2 \leq A \leq 20

1 \leq B \leq 20

Input

Input is given from Standard Input in the following format:

A B

Output

Print the minimum number of power strips required.

Sample Input 1

4 10

Sample Output 1

3

3 power strips, each with 4 sockets, extend the socket into 10 empty sockets.

Sample Input 2

8 9

Sample Output 2

2

2 power strips, each with 8 sockets, extend the socket into 15 empty sockets.

Sample Input 3

8 8

Sample Output 3

1

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using Atcoder;
using System;
using System.Collections.Generic;
using System.ComponentModel.Design;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;

namespace Atcoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var tmp = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            var A = tmp[0];
            var B = tmp[1];
            int ret = 0;
            while (B > 0)
            {
                if (B - A > 0)
                {
                    B -= A - 1;
                    ret++;
                }else
                {
                    if (B > 0)
                    {
                        ret++;
                    }
                    break;
                }
            }
            Console.WriteLine(ret);
        }
        //static void Main(string[] args)
        //{
        //    var temp = new Atcoder.ABC130.D();
        //    temp.Run();
        //}

    }
}