#include <bits/stdc++.h>
using namespace std;
constexpr int N = 1e7 + 55;
bool v[N], ans[N];
int nxt[N];
int main() {
  cin.tie(0)->sync_with_stdio(0);
  for (int i = 1; i < N; ++i) {
    int cur = i;
    while (cur) {
      if (cur % 10 == 7) {
        v[i] = 1;
        break;
      }
      cur /= 10;
    }
  }
  for (int i = 1; i < N; i++) {
    if (!v[i]) continue;
    if (ans[i]) continue;
    for (int j = i; j < N; j += i) {
      ans[j] = 1;
    }
  }
  int las = -1;
  for (int i = N - 1; i >= 0; i--) {
    if (!ans[i]) {
      nxt[i] = las;
      las = i;
    }
  }
  int t;
  cin >> t;
  while (t--) {
    int x;
    cin >> x;
    if (ans[x]) cout << -1 << "\n";
    else cout << nxt[x] << "\n";
  }
  return 0;
}