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: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace abc139
{
    class Program
    {

        public static int hantei(int x, int y)
        {
            int count = 0;
            for (int i = 1; i < y; i = i + x - 1)
            {
                count += 1;
            }
            return count;
        }

        static void Main(string[] args)
        {
            string[] P = Console.ReadLine().Split(' ');
            int A = int.Parse(P[0]);
            int B = int.Parse(P[1]);
            Console.WriteLine(hantei(A, B));
            Console.Read();
        }
    }
}