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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

'use strict'

const main = input => {
	const args = input.split('\n').map(arg => arg.split(' '))
	const A = parseInt(args[0][0], 10)
	const B = parseInt(args[0][1], 10)
	let num = 1

	while (true) {
		const sum = (A - 1) * num + 1
		if (sum >= B) break
		num++
	}

	console.log(num)
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))