#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pii;
const int N = 2E5 + 10, mod = 1E9 + 7;
bool chmax(int &a, int b) {
	if (a < b) {
		a = b;
		return 1;
	}
	return 0;
}
bool chmin(int &a, int b) {
	if (a > b) {
		a = b;
		return 1;
	}
	return 0;
}

void printv(vector<int> a) {
	for (int i : a) {
		cout << i << ' ';
	}
	cout << '\n';
}
void solve() {
	int n, k;
	cin >> n >> k;
	vector<int> a(n + 1);
	vector<vector<int>> b;
	map<int, int> mp, cnt;
	int m = 0;
	int ans = 1;
	for (int i = 1; i <= n; i ++) {
		cin >> a[i];
		if (mp.count(a[i])) {
			b[mp[a[i]]].emplace_back(1);
			if (!mp.count(a[i] - k)) {
				mp[a[i] - k] = m ++;
				b.push_back({-1});
			} else {
				b[mp[a[i] - k]].emplace_back(-1);
			}
			
		} else {
			mp[a[i]] = m ++;
			b.push_back({1});
			if (!mp.count(a[i] - k)) {
				mp[a[i] - k] = m ++;
				b.push_back({-1});
			} else {
				b[mp[a[i] - k]].emplace_back(-1);
			}
		}
		cnt[a[i]] ++;
		chmax(ans, cnt[a[i]]);
	}
	for (int i = 0; i < m; i ++) {
		int q = b[i].size();
		vector<int> s(q + 1);
		int sum = 0;
		int have1 = 0, have2 = 0;
		for (int j = 0; j < q; j ++) {
			s[j + 1] = s[j] + b[i][j];
			if (b[i][j] == -1) sum ++;
			if (b[i][j] == -1) {
				have1 = 1;
			} else {
				have2 = 1;
			}
		}
		if (!have1 || !have2) continue;
		int Min = 0;
		for (int i = 1; i <= q; i ++) {
			chmax(ans, sum + s[i] - Min);
			chmin(Min, s[i]);
		}
	}
	cout << ans << '\n';
} 

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr); cout.tie(nullptr);
	int t = 1;
	//cin >> t;
	while (t --) {
		solve();
	}
	return 0;
}