#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using ll = long long;
using pll = pair<ll, ll>;
using i64 = __int128_t;

int sieve[10000001];
vector<ll> p, v;

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0); cout.tie(0);

  for (int i = 2; i <= 10000000; i++) {
    if (!sieve[i]) {
      p.push_back(i);
      for (int j = 2; i*j <= 10000000; j++) {
        sieve[i*j] = 1;
      }
    }
  }

  for (int i = 2; i < p.size(); i++) {
    if (p[i]*p[i-1] > 100'000'000'000'000LL) break;
    v.push_back(p[i]*p[i-1]);
  }

  int t;
  cin >> t;
  while (t--) {
    ll x;
    cin >> x;
    int idx = upper_bound(v.begin(), v.end(), x) - v.begin() - 1;
    if (idx >= 0) cout << v[idx] << "\n";
    else cout << "-1\n";
  }
}