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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strconv"
)

type MyScanner struct {
	sc *bufio.Scanner
}

type MyWriter struct {
	stdout io.Writer
}

type MyPut interface{}

func getScanner(fp io.Reader) *bufio.Scanner {
	sc := bufio.NewScanner(fp)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 500001), 500000)
	return sc
}

func getHugeScanner(fp io.Reader, size int) *bufio.Scanner {
	sc := bufio.NewScanner(fp)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, size), size)
	return sc
}

func (mysc *MyScanner)String() string {
	mysc.sc.Scan()
	return mysc.sc.Text()
}

func (mysc *MyScanner)Int() int {
	i, _ := strconv.Atoi(mysc.String())
	return i
}

func (mysc *MyScanner)Int64() int64 {
	i, _ := strconv.ParseInt(mysc.String(), 10, 64)
	return i
}

func (mysc *MyScanner)Float64() float64 {
	i, _ := strconv.ParseFloat(mysc.String(), 64)
	return i
}

func (mw MyWriter)Puts(v MyPut) {
	_, _ = fmt.Fprintf(mw.stdout, "%v\n", v)
}

func Solve(stdin io.Reader, stdout io.Writer) {
	sc := MyScanner{getScanner(stdin)}
	mw := MyWriter{stdout}

	a := sc.Int()
	b := sc.Int()

	num := 1
	ans := 0

	for b > num {
		ans++
		num += a - 1
	}

	mw.Puts(ans)
}

func main() {
	Solve(os.Stdin, os.Stdout)
	return
}