Problem Statement

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.

Sample Input 1

4 4 6

Sample Output 1

5

There are five possible sums: $18=4+4+4+6$, $19=4+4+5+6$, $20=4+5+5+6$, $21=4+5+6+6$ and $22=4+6+6+6$.

Sample Input 2

5 4 3

Sample Output 2

0

Sample Input 3

1 7 10

Sample Output 3

0

Sample Input 4

1 3 3

Sample Output 4

1