#include <bits/stdc++.h>
#define int long long 
using namespace std;

int a[5005];

void solve() {
	int n, d;
	cin >> n >> d;
	
	for (int i = 1; i <= n; i++)
		cin >> a[i];
	
	int ans(0);
	for (int i = 1; i <= n; i++) {
		int l = a[i] - d, r = a[i], sum(0), last(0);
		for (int j = 1; j <= n; j++) {
			int v = a[j];
			if (v < l) v = l;
			if (v > r) v = r;
			if (j > 1) sum += llabs(v - last);
			last = v;
		}
		ans = max(ans, sum);
		
		sum = 0;
		l = a[i], r = a[i] + d;
		for (int j = 1; j <= n; j++) {
			int v = a[j];
			if (v < l) v = l;
			if (v > r) v = r;
			if (j > 1) sum += llabs(v - last);
			last = v;
		}
		ans = max(ans, sum);
	}
	cout << ans << '\n';
}

signed main() {
	ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
	solve();
	return 0;
}