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 Ruby (2.3.3) (judge verdict: Wrong Answer)

require 'pp'

def gets; ARGF.gets; end

class Solver

  def initialize
  end

  def main
    a, b = gets.split.map(&:to_i)

    ans = 0
    if b == 1
      ans = 1
    else
      b -= 1
      ans = (b + (a - 1 - 1)) / (a - 1)
    end

    puts ans
  end
end

if __FILE__ == $0
  Solver.new.main
end