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: Accepted)

<?php
list($a, $b) = explode(' ', trim(fgets(STDIN)));

$a = (int) $a;
$b = (int) $b;


if ($b === 1) {
    echo 0;
    return;
}
$res = 0;
$curr = 0;

while (true) {
    if ($curr >= $b) {
        echo $res;
        break ;
    } elseif ($res > 0) {
        $curr--;
        $curr += $a;
        $res++;
    } else {
        $curr += $a;
        $res++;
    }
}