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: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;

namespace A
{
    class Program
    {
        static void Main(string[] args)
        {
            var AB = Io.ReadSplit<int>();
            var A = AB[0];
            var B = AB[1];

            var c = A;
            var output = 1;
            while (true)
            {
                if (c >= B) break;

                c = c - 1 + A;
                output++;
            }

            Console.WriteLine(output);
        }
    }

    class Io
    {
        public static string Read()
        {
            return Console.ReadLine();
        }

        public static IEnumerable<string> ReadRepeat(int count)
        {
            return Enumerable.Range(0, count).Select(_ => Read());
        }

        public static T Read<T>()
        {
            return (T)Convert.ChangeType(Read(), typeof(T));
        }

        public static IEnumerable<T> ReadRepeat<T>(int count)
        {
            return Enumerable.Range(0, count).Select(_ => Read<T>());
        }

        public static string[] ReadSplit(char devide = ' ')
        {
            return Read().Split(devide);
        }

        public static T[] ReadSplit<T>(char devide = ' ')
        {
            return ReadSplit(devide)
                .Select(s => (T)Convert.ChangeType(s, typeof(T)))
                .ToArray();
        }

        public static IEnumerable<T[]> ReadSplitRepeat<T>(int count, char devide = ' ')
        {
            return Enumerable.Range(0, count).Select(_ => ReadSplit<T>(devide));
        }
    }
}