#include<iostream>
#include<bits/stdc++.h> 

using namespace std;

const int N=5e6+10;
int a[N],cnt[N],b[N];

int main(){
    int n,k;
    cin >> n >> k;
    int count=0;
    for(int i=0;i<n;i++){
        cin >> a[i];
        cnt[a[i]]++;
        count=max(count,cnt[a[i]]);
    }
    if(k==0){
        cout << count << endl;
        return 0;
    }
    for(int i=0;i<n;i++){
        b[a[i]]--;
        b[a[i]+k]++;
        if(b[a[i]]<0) b[a[i]]=0;
        count=max(count,b[a[i]+k]+cnt[a[i]+k]);
    }
    cout << count << endl;
    return 0;
}