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;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.IO.Pipes;
using System.Linq;
using System.Numerics;
using System.Text;
using System.Threading.Tasks;

namespace AtCorders
{
	public class Program
	{
		static void Main(string[] args)
		{
			var ab = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
			int a = ab[0];
			int b = ab[1];
			if (b == 1) {
				Console.WriteLine(0);
				return;
			}

			if (b <= a) {
				Console.WriteLine(1);
			} else {
				int c = b - a;
				int ans = (c + a - 2) / (a - 1) + 1;
				Console.WriteLine(ans);
			}
		}
	}
}