#include <bits/stdc++.h>
#define int long long
#define endl '\n'
int INF = 0x3f3f3f3f3f3f3f3f;
using namespace std;
typedef pair<int, int> PII;
void init()
{
}
void solve()
{
    int n, d;
    cin >> n >> d;
    vector<int> a(n + 1);
    int res = 0;
    for (int _ = 1; _ <= n; _++)
    {
        int maxx = a[_];
        int minn = a[_] - d;
        vector<int> b = a;
        int sum = 0;
        for (int i = 1; i <= n; i++)
        {
            if (a[i] < minn)
            {
                b[i] = minn;
            }
            if (a[i] >= minn && a[i] <= maxx)
            {
                b[i] = a[i];
            }
            if (a[i] > maxx)
            {
                b[i] = maxx;
            }
            if (i >= 2)
            {
                sum += abs(b[i] - b[i - 1]);
            }
        }
        res = max(res, sum);
        minn = a[_];
        maxx = a[_] + d;
        b = a;
        sum = 0;
        for (int i = 1; i <= n; i++)
        {
            if (a[i] < minn)
            {
                b[i] = minn;
            }
            if (a[i] >= minn && a[i] <= maxx)
            {
                b[i] = a[i];
            }
            if (a[i] > maxx)
            {
                b[i] = maxx;
            }
            if (i >= 2)
            {
                sum += abs(b[i] - b[i - 1]);
            }
        }
        res = max(res, sum);
    }
    cout << res << endl;
}
signed main()
{
    ios::sync_with_stdio(false), cin.tie(0);
    int t;
    t = 1;
    //    cin>>t;
    init();
    while (t--)
    {
        solve();
    }
}