#include <bits/stdc++.h>
using namespace std;
int gcd(int o, int p) {
  int a = max(o, p), b = min(o, p);
  if (a % b == 0) {
    return b;
  } else {
    return gcd(b, a % b);
  }
}
int main() {
  long long int a, b, n, mi, ma;
  cin >> a >> b;
  cin >> n;
  vector<int> div;
  vector<int> oo;
  for (int i = 1; i * i <= gcd(a, b); i++) {
    if (gcd(a, b) % i == 0) {
      div.push_back(i);
      if (i * i != gcd(a, b)) {
        div.push_back(gcd(a, b) / i);
      }
    }
  }
  if (a % b == 0) {
    div.push_back(a);
  }
  sort(div.begin(), div.end());
  while (n--) {
    long long int c = div.size(), dd = 0;
    cin >> mi >> ma;
    for (int i = c - 1; i >= 0; i--) {
      if (div[i] >= mi && div[i] <= ma) {
        dd++;
        cout << div[i] << endl;
        break;
      }
    }
    if (dd == 0) {
      cout << -1 << endl;
    }
    dd = 0;
  }
}
