AC

#include<bits/stdc++.h>
using namespace std;
int main(){
	long long num = 0;
	long long n,x,y;
	cin>>n>>x>>y;
	if(x>y){cout<<0;return 0;}
	num = (n-2)*y-(n-2)*x;
    if(num>=0)cout<<num+1;
    else cout<<y-x+1;
	
}