#include <bits/stdc++.h>
//#define int LL
#define INF 2000000000
using namespace std;
typedef long long LL;

const int N = 5e3 + 10;

int a[N];
void solve()
{
    int n, d;
    cin >> n >> d;
    int val = INF;
    for (int i = 1; i <= n; i ++ ) {
        cin >> a[i];
    }
    LL ans = -INF;
    for (int i = 1; i <= n; i ++ ) {
        int l = a[i], r = a[i] + d;
        LL res = 0;
        int b[N];
        memcpy(b,a, sizeof a);
        b[1] = min(b[1], r), b[1] = max(b[1], l);
        for (int j = 2; j <= n; j ++ ) {
            b[j] = min(b[j], r), b[j] = max(b[j], l);
            res += abs(b[j] - b[j - 1]);
        }
        ans = max(ans, res);
    }

    cout << ans;
    //for (int i = 1; i <= n; i ++ ) cout << a[i] << ' ';
}


signed main()
{
    int t = 1;
    while (t -- )
    {
        solve();
    }

    return 0;
}