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 Go (1.6) (judge verdict: Accepted)

package main

import "fmt"

func main() {
	var A, B int
	fmt.Scan(&A, &B)

	ans := exec(A, B)
	fmt.Println(ans)
}

func exec(A, B int) int {
	// 現在の差し込み口の数
	now := 1
	// Aプラグの数
	count := 0

	for {
		if B <= now {
			return count
		}

		count++
		now = now - 1 + A
	}

}