#include <bits/stdc++.h>
using namespace std;
const int N = (int)1e6 + 1;
const int INF = (int)1e9;
const int logN = 20;
int n, k, a[N], Log2[N];
int maxValue[N][21];
int getMax(int l, int r) {
  int k = Log2[r - l + 1];
  return max(maxValue[l][k], maxValue[r - (1 << k) + 1][k]);
}
void solve() {
  cin >> n >> k;
  int minV = INF;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
    maxValue[a[i]][0] = a[i];
    minV = min(minV, a[i]);
  }
  for (int j = 1; (1 << j) < N; ++j) {
    for (int i = 1; i + (1 << j) - 1 < N; ++i) {
      maxValue[i][j] =
          max(maxValue[i][j - 1], maxValue[i + (1 << (j - 1))][j - 1]);
    }
  }
  for (int i = 0; (1 << i) < N; ++i) Log2[(1 << i)] = i;
  for (int i = 1; i < N; ++i) Log2[i] = max(Log2[i], Log2[i - 1]);
  int res = 1;
  for (int i = 2; i <= minV; ++i) {
    bool check = 1;
    for (int j = i; j < N; j += i) {
      int d = getMax(j, min(N - 1, j + i - 1)) - j;
      if (d > k) {
        check = 0;
      }
    }
    if (check) res = i;
  }
  cout << res;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}
