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
# -*- coding: utf-8 -*-
N,A,B=map(int, raw_input().split())
if N==1:    #整数が1個のとき
    if A!=B:    #minとmaxが異なる場合はない
        print 0
    else:
        print 1
else:   #整数が2個以上のとき
    if B<A:
        print 0
    elif B==A:
        print 1  
    elif A<B:
        print A+B+B*(N-2)-(A+B+A*(N-2))+1