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 Rust (1.15.1) (judge verdict: Accepted)

use std::io;
fn main() {
    let mut buft = String::new();
    // io::stdin().read_line(&mut bufs).unwrap();
    io::stdin().read_line(&mut buft).unwrap();
    let ab :Vec<i32> = buft.trim().split_whitespace().map(|x| x.parse::<i32>().unwrap()).collect();
    // println!("{} {}", a, b);
    let mut tot = 1;
    let mut ans = 0;
    while tot < ab[1] {
        tot = tot - 1 + ab[0];
        ans += 1;
    }
    println!("{}", ans);
}