#include <iostream>
#include <cmath>
using namespace std;

int main()
{
	long long n, a, b, x, x0, fatique = 0;
	cin >> n >> a >> b;
	cin >> x0;
	n--;
	while (n--) {
		cin >> x;
		fatique += min(a * (x - x0), b);
		x0 = x;
	}
	cout << fatique;
}