#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define pll pair<ll, ll>
const int N = 3e6 + 50;
const int mod = 998244353;

ll a[N], res, ans = 0, n, k, st[N];
vector<ll> e[N];
vector<ll> v;

void solve()
{
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        a[i] += 1e6;
        e[a[i]].push_back(i);
        if (st[a[i]] == 0)
        {
            st[a[i]] = 1;
            v.push_back(a[i]);
        }

    }
    for (auto it : v) ans = max(ans, (ll)e[it].size());
    if (k == 0)
    {
        cout << ans;
        return ;
    }
    ll p1, p2 = 0, cnt2 = 0, mn = 1e18;
    for (auto it : v)
    {
        p2 = 0, cnt2 = 0, mn = 1e18;
        if (it + k < 0) continue;
        if (st[it + k] == 0) continue;
        for (int i = 0; i < e[it].size(); i++)
        {
            p1 = e[it][i];
            p1 --;
            if (cnt2 < e[it + k].size())
            {
                while (p2 < e[it + k].size() && p1 >= e[it + k][p2])
                {
                    cnt2 ++; p2 ++;
                }
            }

            mn = min(mn, i - 2 * cnt2); 

            p1 ++;
            if (cnt2 < e[it + k].size())
            {
                while (p2 < e[it + k].size() && p1 >= e[it + k][p2])
                {
                    cnt2 ++; p2 ++;
                }
            }
            res = i + 1 - 2 * cnt2;
            //cout << res - mn << '\n';
            ans = max(ans, (ll)(res - mn + e[it + k].size()));
        }
    }
    cout << ans;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    //freopen("C:/Users/fb03C/Desktop/cpp/code0/in.txt", "r", stdin);
    //freopen("C:/Users/fb03C/Desktop/cpp/code0/output/std.txt", "w", stdout);
    ll T = 1;
    //cin >> T;
    while (T --)
    {
        solve();
    }
    return 0;
}