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 PHP (5.6.30) (judge verdict: Wrong Answer)

<?php

$hoge = explode(' ', trim(fgets(STDIN)));

if((int)$hoge[1] === 1) echo "0\n";

$count = 1;
$tmp = (int)$hoge[0];
while(1) {
	if($tmp >= (int)$hoge[1]) break;

	$count++;
	$tmp += (int)$hoge[0];
	$tmp -= 1;

}

echo $count."\n";