#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <queue>
#include <vector>

using namespace std;

const int N = 2e6 + 5;
const int M = 1e6 + 3;

priority_queue <int> q;

vector <int> a[N];
int line[N],exsum[N];
int n,k,x,ans;

int main()
{
	scanf("%d%d",&n,&k);
	for(int i = 1;i <= n;i ++)
	{
		scanf("%d",&x);
		a[x + M].push_back(i);
		ans = max(ans,(int)a[x + M].size());
	}
	for(int i = 0;i < N;i ++)
	{
		if(i + k >= 0 && i + k < N && a[i].size() > 0 && a[i + k].size() > 0)
		{
			int cnt1 = 0,cnt2 = 0,cnt = 0;
			while(!q.empty())
				q.pop();
			while(cnt1 < a[i].size() && cnt2 < a[i + k].size())
			{
				if(a[i][cnt1] < a[i + k][cnt2])
				{
					line[++ cnt] = 1;
					cnt1 ++;
				}
				else
				{
					line[++ cnt] = 2;
					cnt2 ++;
				}
			}
			while(cnt1 < a[i].size())
			{
				line[++ cnt] = 1;
				cnt1 ++;
			}
			while(cnt2 < a[i + k].size())
			{
				line[++ cnt] = 2;
				cnt2 ++;
			}
			exsum[0] = 0;
			for(int j = 1;j <= cnt;j ++)
			{
				if(line[j] == 1) exsum[j] = exsum[j - 1] + 1;
				else exsum[j] = exsum[j - 1] - 1;
			}
			for(int j = cnt;j >= 0;j --)
			{
				q.push(exsum[j]);
				ans = max(ans,q.top() - exsum[j] + (int)a[i + k].size());
			}
		}
	}
	printf("%d",ans);
}