Problem:
Score : 200 points

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

Solution in Kotlin (1.0.0) (judge verdict: Accepted)

import java.util.*


fun main(args: Array<String>){
	val cin = Scanner(System.`in`)
    val n = cin.nextLong()
    val a = cin.nextLong()
    val b = cin.nextLong()

    val c: Long = b - a

    if (0 > c) {
        println(0)
    } else if (n == 1.toLong()) {
        if (c > 0) {
            println(0)
        } else {
            println(1)
        }
    } else {
        val max: Long = b*(n-1) + a
        val min: Long = a*(n-1) + b
        println(max - min + 1)
    }
}