#include <bits/stdc++.h>
const int maxn = 1e6 + 10;
const int py = 1e6;
using namespace std;
vector<int> vec[maxn * 3];
int a[maxn], n, k;
pair<int, int> f[maxn];
int cnt;
int pre[maxn], s[maxn];
int main()
{
    scanf("%d%d", &n, &k);
    for (int i = 1; i <= n; i++)
    {
        scanf("%d", &a[i]);
        a[i] = a[i] + py;
        vec[a[i]].push_back(i);
    }
    int ans = 0;
    for (int now = 0; now <= 2e6; now++)
    { // i and i-k
        
        int prev = now - k;
        ans = max(ans, (int)vec[now].size());
        if (vec[now].empty())
            continue;
        if (prev < 0 || prev > 2e6 || vec[prev].empty())
            continue;
        cnt = 0;
        for (auto v : vec[now])
            f[++cnt] = make_pair(v, 1);
        for (auto v : vec[prev])
            f[++cnt] = make_pair(v, 0);
        sort(f + 1, f + 1 + cnt);
        int ret = 0;
        for (int i = 1; i <= cnt; i++)
        {
            a[i] = f[i].second;
            pre[i] = pre[i - 1] + a[i];
        }
        for (int i = 1; i <= cnt; i++)
        {
            ans = max(ans, pre[cnt] + i - 2 * pre[i] + ret);
            ret = max(ret, 2 * pre[i] - i);
        }
        //cout<<now<<' '<<ans<<endl;
    }
    cout<<ans<<endl;
}