Score : $200$ points
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?
Input is given from Standard Input in the following format:
$N$ $A$ $B$
Print the number of the different possible sums.
4 4 6
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 $22=4+6+6+6$.
5 4 3
0
1 7 10
0
1 3 3
1