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;
using System.Linq;

namespace ABC139_B
{
    class Program
    {
        static void Main(string[] args)
        {
            var AB = Console.ReadLine().Split().Select(int.Parse).ToArray();
            var A = AB[0];
            var B = AB[1];
            if (B == 1)
            {
                Console.WriteLine(0);
                return;
            }

            var ans = 1;
            var sum = A;
            while (true)
            {
                if (sum >= B)
                {
                    break;
                }
                ans++;
                sum += A - 1;
            }

            Console.WriteLine(ans);
        }
    }
}