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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;
public class Main {

    public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
    	// 入力
    	int a = sc.nextInt();
    	int b = sc.nextInt();

    	int ans = 0;
    	int sum = 0;

    	if (b != 1){
    		for (int i = 0; true; i++){
    			ans++;
    			sum = sum + (a - 1);
    			if (b <= sum + 1){
    				break;
    			}
    		}
    	}

    	// 出力
    	System.out.println(ans);
    }
}