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

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int n, k;
  cin >> n >> k;
  vector<int> a(n);
  map<int, vector<int>> mp;
  int ans = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    mp[a[i]].push_back(i);
    ans = max(ans, int(mp[a[i]].size()));
  }
  for (auto &[v, b] : mp) {
    if (mp.find(v + k) == mp.end()) continue;
    auto &c = mp[v + k];
    vector<int> d(b.size() + c.size());
    merge(b.begin(), b.end(), c.begin(), c.end(), d.begin());
    int cur = 0, mn = 0;
    for (auto id : d) {
      if (a[id] == v) cur++;
      else cur--;
      mn = min(mn, cur);
      ans = max(ans, cur - mn + int(c.size()));
    }
  }
  cout << ans << "\n";
  return 0;
}