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: Accepted)

$debug = false
flag = ARGV.shift
if flag == "-d"
  $debug = true
end

def dputs str
  p str if $debug
end

def max(n, m)
  if n > m
    return n
  else
    return m
  end
end

def min(n, m)
  if n < m
    return n
  else
    return m
  end
end

def gets_all_int
  return gets.chomp.split.map{|v| v.to_i}
end

## start

A, B = gets_all_int

# sockets = A * n - (n - 1)

taps = 0
0.upto(B) do |n|
  if n == 0
    sockets = 1
  else
    sockets = A * n - (n - 1)
  end
  dputs "sockets = #{sockets}, n=#{n}"
  if sockets >= B
    taps = n
    break
  end
end

puts taps