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 abc139
{
    class abc139b
    {
        static void Main(string[] args)
        {
            var buf = Console.ReadLine().Split();
            var a = int.Parse(buf[0]);
            var b = int.Parse(buf[1]);
            var r = Solve(a, b);
            Console.WriteLine(r);
        }

        static int Solve(int a, int b)
        {
            var n = 0;
            var r = 1;
            do {
                ++n;
                r += a - 1;
            } while(r < b);
            return n;
        }
    }
}