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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.*;
import java.util.*;

public class Main {

    static class InputReader {
        BufferedReader reader;
        StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null; }
        String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try { tokenizer = new StringTokenizer(reader.readLine()); } 
                catch (IOException e) { throw new RuntimeException(e);} }
            return tokenizer.nextToken(); }
        public int nextInt() { return Integer.parseInt(next()); }
        public long nextLong() { return Long.parseLong(next()); }
        public double nextDouble() { return Double.parseDouble(next()); }
    }

    static InputReader r = new InputReader(System.in);
    static PrintWriter pw = new PrintWriter(System.out);

    public static void main(String[] args) {
        
        int a = r.nextInt();
        int b = r.nextInt();
        // each socket adds A-1;

        pw.println((int)Math.ceil((1.0 * b-1) / (a-1)));

        pw.close();
    }
}

/**
                _        _                 _                                                
               | |      | |               | |                                               
   ___ ___   __| | ___  | |__  _   _    __| | __ _ _ __ _ __ ___ _ __     _   _  __ _  ___  
  / __/ _ \ / _` |/ _ \ | '_ \| | | |  / _` |/ _` | '__| '__/ _ \ '_ \   | | | |/ _` |/ _ \ 
 | (_| (_) | (_| |  __/ | |_) | |_| | | (_| | (_| | |  | | |  __/ | | |  | |_| | (_| | (_) |
  \___\___/ \__,_|\___| |_.__/ \__, |  \__,_|\__,_|_|  |_|  \___|_| |_|   \__, |\__,_|\___/ 
                                __/ |                               ______ __/ |            
                               |___/                               |______|___/             
 */