#include <iostream>
#include <map>
using namespace std;
const int maxn = 1e6 + 1;
int a[maxn];
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(0);
    int n, k;
    cin >> n >> k;
    auto cnt = map<int, int>(), cur = cnt, Min = cnt, f = cnt;
    // cur[x]=count of x-k -count of x
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        ++cnt[a[i]];
        // Min[a[i]] = min(Min[a[i]], --cur[a[i]]);
        Min[a[i]] = min(Min[a[i]], cur[a[i]] = cnt[a[i] - k] - cnt[a[i]]);
        Min[a[i] + k] = min(Min[a[i] + k], cur[a[i] + k] = cnt[a[i]] - cnt[a[i] + k]); // 0 is always valid
        f[a[i]] = max(f[a[i]], cur[a[i]] - Min[a[i]]);                                 // changing a[i]-k to a[i], where r=i
        f[a[i] + k] = max(f[a[i] + k], cur[a[i] + k] - Min[a[i] + k]);
    }
    int ans = 0;
    for (const auto [k, v] : cnt)
        ans = max(ans, v + f[k]);
    cout << ans;
}