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;

public class Test {
  public static void Main() {
    string[] input = Console.ReadLine().Trim().Split(' ');    
    int A = int.Parse(input[0]);
    int B = int.Parse(input[1]);
    int sum = 0;
    int count = 0;
    
    if(B == 1) {
      Console.WriteLine(0);
      return;
    }
    while(sum < B) {
      if(sum == 0) {
        sum += A;
      } else {
        sum += (A - 1);
      }
      count++;
    }
    Console.WriteLine(count);  
  }
}