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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

class Prog{
  static void Main(){
    int[] ls = Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
    int a = ls[0];
    int b = ls[1];
    int i = 0;
    while(a +(a-1)*i - b < 0){
      i++;
    }
    if(b != 1){
      Console.WriteLine(i+1);
    }else{
      Console.WriteLine(0);
    }
  }
}