#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1)
#define TASK "task"
#define sz(s) (int) (s).size()
 
using namespace std;
const int mxN = 5e5 + 227;
const int inf = 1e9 + 277;
const int mod = 1e9 + 7;
const ll infll = 1e18 + 7;
const int base = 307;
const int LOG = 20;
 
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
    if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
    if (a < b) {a = b; return true;} return false;
}
 
int n;
int d;
int a[mxN];
 
void solve()
{
    cin >> n >> d;
    for(int i = 1; i <= n; i++) cin >> a[i];
    int res = 0;
    for(int i = 1; i <= n; i++) {
        int l = a[i];
        int r = a[i] + d;
        int sum = 0;
        for(int j = 1; j < n; j++) {
            int x = a[j];
            int y = a[j + 1];
            if(x < l) x = l;
            if(x > r) x = r;
            if(y < l) y = l;
            if(y > r) y = r;
            sum += abs(x - y);
        }
        maximize(res, sum);
    }
    cout << res;
}
 
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
 
    int tc = 1;
    //cin >> tc;
    while(tc--) {
        solve();
    }
    return 0;
}