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.IO;
using System.Collections.Generic;
using System.Numerics;

namespace abc139
{
    class Program
    {
        static void Main(string[] args)
        {
            //Console.SetIn(new StreamReader("input.txt"));
            solve_abc139B();
        }
        public static void solve_abc139B()
        {
            string[] ab = Console.ReadLine().Split(' ');
            int a = Convert.ToInt32(ab[0]);
            int b = Convert.ToInt32(ab[1]);

            int w = a > b ? a : (b + a - 1) / a;
            int d = w - 1;
            int r = a * w - d;
            if (r < b)
            {
                w++;
            }

            Console.WriteLine(w);

            /*
            //Округление вверх не работает. Узнать почему
            int t = (b + a - 1) / a;
            int d = t - 1;
            if (b > a * t - d)
            {
                t++;
            }
            Console.WriteLine(t);
            */
        }

        public static void solve_abc139A()
        {
            string s1 = Console.ReadLine();
            string s2 = Console.ReadLine();

            int c = 0;

            if (s1[0] == s2[0])
            {
                c++;

            }
            if (s1[1] == s2[1])
            {
                c++;
            }
            if (s1[2] == s2[2])
            {
                c++;
            }
            Console.WriteLine(c);
        }
    }
}