#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
int n,k,a[1000005];
vector<int> pos[5000005];
int ans;
int main(){
	cin>>n>>k;
	for (int i=1;i<=n;i++){
		scanf("%d",&a[i]);
		a[i]+=2000000;
		pos[a[i]].push_back(i);
	}
	for (int i=0;i<=5000000;i++){
		ans=max(ans,(int)pos[i].size());
		if (i-k<0||i-k>5000000)continue;
		int p0=0,p1=0;
		int f=0,mx=0;
		while(p0<pos[i].size()&&p1<pos[i-k].size()){
			if (pos[i][p0]<pos[i-k][p1])f--,p0++;
			else f++,p1++;
			f=max(f,0);
			mx=max(mx,f);
		}
		while(p0<pos[i].size()){
			f--,p0++;
			f=max(f,0);
			mx=max(mx,f);
		}
		while(p1<pos[i-k].size()){
			f++,p1++;
			f=max(f,0);
			mx=max(mx,f);
		}
		ans=max(ans,mx+(int)pos[i].size());
	}
	cout<<ans<<endl;
	return 0;
}