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

using isize = size_t;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
using i128 = __int128_t;
using u128 = __uint128_t;
using f64 = long double;
using p2 = pair<i64, i64>;
using el = tuple<i64, i64, i64>;
using mint = atcoder::modint998244353;

void _main();
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(18);
  _main();
}

i64 pow(i64 x, i64 n) {
  i64 res = 1;
  i64 t = x;
  while (n > 0) {
    if (n & 1) res *= t;
    t *= t;
    n >>= 1;
  }
  return res;
}

void _main() {
  i64 t;
  cin >> t;
  for (;t--;) {
    i64 n, k;
    cin >> n >> k;
    i64 ans = -1;
    for (i64 i = n; i > k; i--) {
      bool ok = true;
      for (i64 j = 2; j * j <= i; j++) {
        if (j > k) break;
        if (i % j == 0 && i / j <= k) {
          ok = false;
          break;
        }
      }
      if (ok) {
        ans = i;
        break;
      }
    }
    cout << ans << "\n";
  }
}