#include <bits/stdc++.h>
#define int long long
using namespace std; 
const int maxn = 1e6 + 5;
int n, k, a[maxn];
std::vector <int> po[maxn<<1];
int cnt[maxn<<1];
signed main() 
{
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    set<int>xiaoyu;
    cin >> n >> k; for(int i = 1; i <= n; i++) 
    {
    	cin >> a[i], a[i] += 1e6, cnt[a[i]] ++, po[a[i]].emplace_back(i);
    	xiaoyu.insert(a[i]);
	}
    int ans = 0;
    for(auto i:xiaoyu)
	 {
        ans = std::max(ans, cnt[i]);
        if(i + k <= 2e6 && i + k >= 0 && cnt[i + k])
		 {
            int p = 0, q = 0, cur = 0;
            while(p < (int) po[i].size() && q < (int) po[i + k].size()) {
                if(po[i][p] < po[i + k][q]) {
                    cur ++;
                    p ++;
                } else {
                    cur --;
                    q ++;
                }
                cur = std::max(0ll, cur);
                ans = std::max(ans, cnt[i + k] + cur);
            }
            if(p<(int)po[i].size())
			   ans = std::max(ans, cnt[i + k] + cur + (int) po[i].size() - p);
        }
    }
    cout << ans << '\n';
    return 0;
}