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 PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
  $arr = explode(" ",trim(fgets(STDIN)));
  if($arr[0]<$arr[1]) {
    $ok = true;
    $res = 0;
    $cnt = 0;
    while($ok) {
     $res += $arr[0];
     $cnt++;
     if($res>=$arr[1]){
        echo $cnt;
        $ok = false;
     }
     else {
        $res--;
     }
    }
  }
  else {
      echo 1;
  }