#include<iostream>
#include<algorithm>
#include<vector>
#include<map>
#include<array>
#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 ln cout<<'\n'
#define B begin()
#define pb push_back
#define D end()
#define pii pair<int,int> 

using namespace std;
const int N=3e6+10;
const int mod=1e9;  
int cnt[N],ma[N];
int ji[N];
void solve()
{
int n,k;cin>>n>>k;
	int d=1000010;
	vector<int>a(n);
	for(auto &x:a)
	{
		cin>>x;
		ji[x]++;
	}
	if(k==0)
	{
		int ans=0;
    for(int i=-1000000;i<=1000000;i++)
	{
		ans=max(ans,ji[i]);
	}
		cout<<ans<<'\n';
		return ;
	}
	for(auto x:a)
	{
		if(x+k>=-1000000&&x+k<=1000000)
		{
			cnt[x+d]++;
			ma[x+d]=max(ma[x+d],cnt[x+d]);
		}
		if(((x-k)>=-1000000)&&((x-k)<=1000000))
		{
			cnt[x-k+d]--;
			cnt[x-k+d]=max(0ll,cnt[x-k+d]);
			ma[x-k+d]=max(ma[x-k+d],cnt[x+d-k]);
		}
		//cout<<ma[x+d]<<' '<<cnt[x+d]<<'\n';
	}
	int ans=0;
	for(int i=-1000000;i<=1000000;i++)
	{
		int x=i,y=ji[i];
		if(((x-k)>=-1000000)&&((x-k)<=1000000))
		{
			ans=max(ans,y+ma[x-k+d]);//cout<<x<<' '<<y<<'\n';
		}else ans=max(ans,y);	
	}
	cout<<ans;
}
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int tc=1;
	//cin>>tc;
	while(tc--)
	{
		solve();
	}
	//cout<<"dafc";
	return 0;
}