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]) {
     $c = intdiv($arr[1],$arr[0])+1;
     $res = $arr[0]*$c-($c-1);
     if($res>=$arr[1]) {
         echo $c;
     }
     else {
      $ok = true;
      while($ok) {
        $res += $arr[0]-1;
        $c++;
        if($res>=$arr[1]) {
         echo $c;
         $ok = false;
        }
      }
    }
  }
  else {
      echo 1;
  }