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 Python (3.4.3) (judge verdict: Accepted)


def main():
    n,a,b=map(int,input().split())

    if n == 0:
        ans=0
        print(ans)
        return
    elif n==1:
        if a==b:
            ans=1
            print(ans)
            return
        else:
            ans=0
            print(ans)
            return

    elif n>=2:
        ans=1
        if a>b:
            ans=0
            print(ans)
            return
# ありうる数字の種類
        dif=b-a
        #数
        num=n-2
        ans=dif*num+1
        print(ans)




if __name__ == '__main__':
    main()