#include <bits/stdc++.h>

int main()
{
	int n;
	long long pre_x, a, b, count{};
	scanf("%d%lld%lld", &n, &a, &b);
	scanf("%lld", &pre_x);
	for (int i = 1; i < n; i++)
	{
		long long x;
		scanf("%lld", &x);
		count += std::min(b, a * (x - pre_x));
		pre_x = x;
	}
	printf("%lld\n", count);

	return 0;
}