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: Accepted)

'use strict'

function Main(input) {
  const A = input.split(" ")[0]
  let B = input.split(" ")[1]
  let ans = 0

  if(B <= 1) {
    console.log(0)
    return
  }
  
  for(let i=0; i<100; i++) {
    if(i === 0) {
      B -= A
    } else {
      B -= (A - 1)
    }
    ans++
    if(B <= 0) {
      break
    }
  }
  console.log(ans)
}

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