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 Python (3.4.3) (judge verdict: Wrong Answer)

import math
A, B=map(int, input().split())

if B==1:
  print(0)
else:
  if math.ceil(B/A)==1:
    print(1)
  else:
    if (A-1)==1:
      print(B//(A-1))
    else:
      if (B-A)%(A-1)==0:
        print((B-A)//(A-1)+1)
      else:
        print((B-A)//(A-1)+2)