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# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Globalization;
using System.IO;
using System.Text;
using static Scanner;

class Program
{
    static void Main(string[] args) {
        var writer = new StreamWriter(Console.OpenStandardOutput()) {AutoFlush = false};
        Console.SetOut(writer);
        Solve();
        Console.Out.Flush();
    }
    static void Solve() {
        int A = ScanInt(), B = ScanInt();
        var answer = 0;
        for (var soc = 1; soc < B; soc += A - 1) answer++;
        Console.WriteLine(answer);
    }
}

public static class Scanner
{
    static readonly Stream stream = Console.OpenStandardInput();
    static readonly byte[] buffer = new byte[1024];
    static int length, p;
    static bool isEof;
    private static byte ConsoleIn() {
        if (isEof) return 0;
        if (p < length) return buffer[p++];
        p = 0;
        if ((length = stream.Read(buffer, 0, 1024)) > 0) return buffer[p++];
        isEof = true;
        return 0;
    }
    public static char GetChar() {
        var by = ConsoleIn();
        while ((by < '!' || '~' < by) && !isEof) by = ConsoleIn();
        return (char) by;
    }
    public static int ScanInt() {
        var temp = 0;
        for (var ch = GetChar(); '0' <= ch && ch <= '9'; ch = (char) ConsoleIn()) {
            temp = temp * 10 + ch - '0';
        }
        return temp;
    }
}