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;
using System.Text;
using System.Threading.Tasks;

namespace AtCoder
{
    class Program
    {
        static void Main()
        {
            Solve();

            Console.ReadKey();
        }

        static void Solve()
        {
            var str = IO.GetIntList();
            var ans = 0;
            var num = 1;
            while (num >= str[1])
            {
                num += str[1] - 1;
                ans += 1;
            }

            Console.WriteLine(ans);
        }
    }


    static class IO
    {
        static public string GetString() { return Console.ReadLine(); }
        static public int GetInt() { return int.Parse(Console.ReadLine()); }
        static public long GetLong() { return long.Parse(Console.ReadLine()); }
        static public List<string> GetStringList() { return Console.ReadLine().Split(' ').ToList(); }
        static public List<int> GetIntList() { return Console.ReadLine().Split(' ').Select(int.Parse).ToList(); }
        static public List<long> GetLongList() { return Console.ReadLine().Split(' ').Select(long.Parse).ToList(); }
        static public List<double> GetDoubleList() { return Console.ReadLine().Split(' ').Select(double.Parse).ToList(); }
        static public void WriteStrings<T>(IEnumerable<T> values) { foreach (var o in values) { Console.Write(o + " "); } }
    }
}