#include <bits/stdc++.h>
using namespace std;
long long int ceil2(long long int a, long long int b) {
  return (a + b - 1) / b;
}
long long int hcf(long long int n1, long long int n2) {
  if (n2 != 0)
    return hcf(n2, n1 % n2);
  else
    return n1;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int q;
  long long int a, b, li, hi;
  cin >> a >> b;
  cin >> q;
  int gcd = hcf(a, b);
  map<int, int> m;
  vector<long long int> ice;
  while (gcd % 2 == 0) {
    ice.push_back(2);
    gcd /= 2;
  }
  for (int i = 3; i * i <= gcd; i++) {
    while (gcd % i == 0) {
      ice.push_back(i);
      gcd /= i;
    }
  }
  if (gcd > 1) {
    ice.push_back(gcd);
  }
  int sz = ice.size();
  vector<long long int> requim;
  requim.push_back(1);
  int zx = requim.size();
  for (int i = 0; i < sz; i++) {
    for (int j = 0; j < zx; j++) {
      requim.push_back(requim[j] * ice[i]);
    }
    zx = requim.size();
  }
  sort(requim.begin(), requim.end());
  for (int i = 0; i < q; i++) {
    cin >> li >> hi;
    int pos = upper_bound(requim.begin(), requim.end(), hi) - requim.begin();
    if (pos == (zx + 1)) {
      cout << -1 << endl;
    } else if (pos == 0) {
      cout << -1 << endl;
    } else if (requim[pos - 1] >= li) {
      cout << requim[pos - 1] << endl;
    } else {
      cout << -1 << endl;
    }
  }
  return 0;
}
