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 JavaScript (node.js v5.12) (judge verdict: Accepted)

function Main(input) {
  input = input.split("\n");
  tmp = input[0].split(" ");
  var answer = 0;
  var plug = tmp[1];
  tap = tmp[0]-1;
  if(tmp[1] != 1){
    plug = tmp[1]-tmp[0];
    answer++;
    while(plug > 0){
      plug = plug-tap;
      answer++;
    }
  }
  console.log(answer);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));