Snuke has N integers. Among them, the smallest is A, and the largest is B. We are interested in the sum of those N integers. How many different possible sums there are?

Constraints

* 1 ≤ N,A,B ≤ 10^9
* A and B are integers.

Input

Input is given from Standard Input in the following format:


N A B


Output

Print the number of the different possible sums.

Examples

Input

4 4 6


Output

5


Input

5 4 3


Output

0


Input

1 7 10


Output

0


Input

1 3 3


Output

1
def a_plus_b():
	n, a, b = map(int, raw_input().split(" "))
	if a>b:
		print 0
		return
	if n==1:
		if a==b:
			print 1
		else:
			print 0
		return
	min_sum = a*(n-1)+b
	max_sum = b*(n-1)+a
	print max_sum-min_sum+1


if __name__ == "__main__":
	a_plus_b()