#include <bits/stdc++.h>

using namespace std;

const int D = 1e6 + 2;

vector<int> M[(D << 1) + 6];
vector< pair<int, int> > id;

signed main()
{
    int n, m;
    scanf("%d%d", &n, &m);
    for (int i = 1, x; i <= n; ++i) {
        scanf("%d", &x);
        M[x + D].push_back(i);
    }
    int res = 0;
    for (int i = -D; i <= D; ++i) {
        id.clear();
        if (M[i + D].empty()) {
            continue;
        }
        for (auto x : M[i + D]) {
            id.push_back(make_pair(x, -1));
        }
        if (i - m >= -D && i - m <= D) {
            for (auto x : M[i - m + D]) {
                id.push_back(make_pair(x, 1));
            }
        }
        sort(id.begin(), id.end());
        int s = 0, mx = 0;
        for (auto [x, y] : id) {
            s += y;
            if (s < 0) {
                s = 0;
            }
            mx = max(mx, s);
        }
        res = max(res, mx + (int)M[i + D].size());
    }
    printf("%d\n", res);
    return 0;
}