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;
class Program
{
	static void Main(string[] args)
	{
		// 整数の入力
		//int a = int.Parse(Console.ReadLine());
		// スペース区切りの整数の入力
		string[] input = Console.ReadLine().Split(' ');
		int A = int.Parse(input[0]);
		int B = int.Parse(input[1]);
		// 文字列の入力
		//string s = Console.ReadLine();
		//出力
      
		Console.WriteLine(((B-A) % (A-1)>0) ?(B-A) / (A-1) + 2:(B-A) / (A-1) + 1);
	}
}