不正经题解

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