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: Time Limit Exceeded)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace A
{
    class Program
    {
        /// <summary>
        ///   The main entry point for the application
        /// </summary>
        [STAThread]
        public static void Main(string[] args)
        {
            string[] str = Console.ReadLine().Split(' ');//2つ以上のスペース区切り入力の取得
            int a = int.Parse(str[0]);
            int b = int.Parse(str[1]);
            int use = 1;
            int now = 1;
            while(true) {
                if(b <= now) {
                    Console.Write("{0}", use);
                }
                now = now - 1 + a;
                use++;
            }
        }
    }
}