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 Scala (2.11.7) (judge verdict: Wrong Answer)

import java.util.Scanner



object Main {

  def read(): (Int, Int) = {
    val sc: Scanner = new Scanner(System.in)
    val a, b= sc.nextInt
    sc.close()
    (a, b)
  }


  def solve(a: Int, b: Int): Int = {
    var cnt = 0
    while(b > a * cnt - Math.max(cnt-1, 0)) {
      cnt += 1
    }
    cnt
  }


  def main(args: Array[String]): Unit = {
    val (a, b) = read()
    println(solve(a, b))
  }

}