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 tmp = input.trim().split(' ')
  const A = parseInt(tmp[0])
  const B = parseInt(tmp[1])

  let sockets = A
  let count = 1

  while (sockets < B) {
    sockets += A - 1
    count += 1
  }

  let result = count

  console.log(result)
  return result
}

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