#include <bits/stdc++.h>
using namespace std;
#define uint unsigned long long
#define int long long
#define endl '\n'
const int N = 2e6 + 5;
typedef pair<int, int> PII;
#define MAX LONG_LONG_MAX
int ar[N];
int mp[N * 4], t[N * 4];
void solve()
{
    int n, m, ans = 0;
    cin >> n >> m;

    for (int i = 1; i <= n;i ++)
    {
        cin >> ar[i], ar[i] += N;
        mp[ar[i]]++;
        ans = max(ans, mp[ar[i]]);
    }
    if(!m)
    {
        cout << ans << endl;
        return;
    }
    for (int i = 1; i <= n; i++)
    {
        t[ar[i]] = max(t[ar[i]] - 1, 0ll);
        t[ar[i] + m]++;
        ans = max(ans, t[ar[i] + m]);
    }
    cout << ans << endl;
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);

    solve();
    return 0;
}