#include<iostream>
#include<algorithm>
#include<vector>
#include<map>
#include<random>
#include<string>
#include<time.h>
#include<cstring>
#include<set>
#include<cmath>
#include<queue>
#define int long long
#define endl '\n'
#define F first
#define S second
#define sz size()
#define B begin()
#define pb push_back
#define D end()
#define pii pair<int,int> 
#define ln cout<<'\n'
using namespace std;
typedef long long ll;
const int N=2e6+10;
const int P=1331;
const int mod=1e9+7;
void solve()
{
	int n,d;cin>>n>>d;
	vector<int>a(n+1),b(n+1);
	for(int i=1;i<=n;i++) cin>>a[i];
	int ans=0;
	for(int i=1;i<=n;i++)
	{
		int l=a[i];int r=a[i]+d;int op=0;
		for(int j=1;j<=n;j++)
		{
			b[j]=min(r,a[j]);
			b[j]=max({op,l,b[j]});
		}
		int cnt=0;
		for(int j=1;j<n;j++)
		{
			cnt+=abs(b[j+1]-b[j]);
		}
		ans=max(ans,cnt);
		cnt=0;l=max(op,a[i]-d);
		r=l+d;
		for(int j=1;j<=n;j++)
		{
			b[j]=min(r,a[j]);
			b[j]=max({op,l,b[j]});
		}
		cnt=0;
		for(int j=1;j<n;j++)
		{
			cnt+=abs(b[j+1]-b[j]);
		}
	}
	cout<<ans;
}
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int tc=1;
	//cin>>tc;
	while(tc--)
	{
		solve();
	}
	return 0;
}