#include <bits/stdc++.h>
using namespace std;

#define x first
#define y second
typedef pair<int, int> PII;
typedef long long ll;

void solve()
{
    int n, k;
    cin >> n >> k;
    vector<int> a(n);
    for(auto &t : a) cin >> t, t += 1e6;
    vector<vector<int>> idx(2e6 + 1);
    for(int i = 0; i < n; i++) idx[a[i]].push_back(i);
    int ans = 0;
    for(int i = 0; i <= 2e6; i++) if(idx[i].size())
    {
        if(i - k < 0 || i - k >= 2e6 || idx[i - k].size() == 0) ans = max(ans, (int)idx[i].size());
        else
        {
            ans = max(ans, (int)idx[i].size());
            vector<int> v{0};
            int j1 = 0, j2 = 0;
            while(j1 < idx[i].size() || j2 < idx[i - k].size())
            {
                if(j1 < idx[i].size() && j2 < idx[i - k].size())
                {
                    if(idx[i][j1] < idx[i - k][j2]) v.push_back(1), j1++;
                    else v.push_back(0), j2++;
                }
                else if(j1 < idx[i].size()) v.push_back(1), j1++;
                else v.push_back(0), j2++;
            }
            int m = v.size() - 1;
            for(int j = 1; j <= m; j++) v[j] += v[j - 1];
            int mx = -10;
            for(int j = 1; j <= m; j++)
            {
                mx = max(mx, 2 * v[j - 1] - j);
                ans = max(ans, mx + j + 1 - 2 * v[j] + v[m]);
            }
        }
    }
    cout << ans << '\n';
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    // int T; cin >> T; while(T--)
    solve();
    return 0;
}