#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;

const int MAXN = 1e6 + 10;

inline int read() {
	int x = 0, f = 1;
	char ch = getchar();
	while (!isdigit(ch)) {
		if (ch == '-') f = -1;
		ch = getchar();
	}
	while (isdigit(ch)) {
		x = x * 10 + ch - '0';
		ch = getchar();
	}
	return x * f;
}

int n, k, a[MAXN];
int sum[MAXN << 2], Sum[MAXN][4];
vector<int> G[MAXN << 2];
int minn[MAXN << 2];

int main() {
	n = read(); k = read();
	for (int i = 1; i <= n; i++) {
		a[i] = read();
		sum[a[i] + 2 * MAXN]++;
		Sum[i][0] = sum[a[i] + 2 * MAXN];
		Sum[i][1] = sum[a[i] + 2 * MAXN - k];
		Sum[i][2] = sum[a[i] + 2 * MAXN + k];
		G[a[i] + 2 * MAXN].push_back(i);
		G[a[i] + 2 * MAXN + k].push_back(i);
	}	
//	for (int i = 1; i <= n; i++)
//		cout << Sum[i][0] << " " << Sum[i][1] << " " << Sum[i][2] << endl;
	int ans = -MAXN;
	for (int i = 0; i < (MAXN << 2); i++) {
		for (int j = 0; j < G[i].size(); j++) {
			//cout << minn[i] << " ";
			int x = G[i][j];
			if (a[x] + 2 * MAXN == i) {
				//cout << Sum[x][1] - Sum[x][0] + 1 << "A ";
				ans = max(ans, sum[i] + Sum[x][1] - Sum[x][0] - minn[i]);
				minn[i] = min(minn[i], Sum[x][1] - Sum[x][0] + 1);
			}
			if (a[x] + 2 * MAXN == i - k) {
				//cout << Sum[x][0] - Sum[x][2] - 1 << "B ";
				ans = max(ans, sum[i] + Sum[x][0] - Sum[x][2] - minn[i]);
				minn[i] = min(minn[i], Sum[x][0] - Sum[x][2] - 1);
			}
			//cout << ans << endl;
		}
		//if (G[i].size() != 0) cout << endl; 
		ans = max(ans, sum[i]);
	}
	printf("%d\n", ans);
	return 0;
}