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
import java.math.BigInteger;
import java.util.*;
public class Main {
	
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        long N = sc.nextLong();
        long A = sc.nextLong();
        long B = sc.nextLong();
        
        if (A > B || (N == 1 && A != B)) {
        	System.out.println(0);
        	return;
        }
        
        //処理
        if (N == 2) {
        	System.out.println(3);
        	return;
        }
        N -=2;
        
        String ans = BigInteger.valueOf(B).multiply(BigInteger.valueOf(N)).subtract(BigInteger.valueOf(A).multiply(BigInteger.valueOf(N))).add(BigInteger.ONE).toString(10);
        
        System.out.println(ans);
    }
}

