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
#include<bits/stdc++.h>
using namespace std;
typedef long long l;
l max(l a,l b){
    if(a>b) return a;
    else return b;
}
int main(){
    l a,b,c;
    cin>>a>>b>>c;
    cout<<max((a-2)*(c-b)+1,0)<<endl;
}
