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 (1.42.0) (judge verdict: Accepted)

use text_io::*;
use std::process::exit;

fn main() {
    let a:usize = read!();
    let b:usize = read!();
    let mut c:usize = 1;
    if b == 1 {
        println!("0");
        exit(0)
    }
    for i in 0..30 {
        c += a-1;
        if b<=c {
            println!("{}",i+1);
            exit(0)
        }
    }
}