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 JavaScript (node.js v5.12) (judge verdict: Accepted)

"use strict"
 
function Main(input) {
  input = input.trim().split(' ').map(Number);
  const A = input[0];
  const B = input[1];
 
  let ret = 0;
  let tmp = 0;
  while(true){
    if(tmp >= B || B === 0 || B === 1) break;
    if(ret === 0) {
      tmp += A;
    } else {
      tmp += A-1;
    }
    ret++
  }
  console.log(ret);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));