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: Wrong Answer)

fun main(args: Array<String>) {
    agc015a()
}

fun agc015a() {
    val (n, a, b) = readLine()!!.split(' ').map { it.toInt() }

    if (a > b || a + n + 1 < b) return println(0)
    if (n == 1) return if (a != b) println(0) else println(1)
    if (n == 2) return println(1)

    val answer = (a + b * (n - 1)) - (a * (n - 1) + b) + 1

    println(answer)
}