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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int main(void)
{
	int a, b, ans;
	scanf("%d %d", &a, &b);

	if (b != 1)
	{
		ans = 1;
		if (b - a >= a - 1)
		{
			if ((b - a) % (a - 1) == 0)
				ans += (b - a) / (a - 1);
			else
				ans += (b - a) / (a - 1) + 1;
		}
	}
	else
		ans = 0;
	printf("%d\n", ans);
	return 0;
}