#include <bits/stdc++.h>
using namespace std;
long long GCD(long long a, long long b) { return (a) ? GCD(b % a, a) : b; }
long long LCM(long long a, long long b) { return a * b / GCD(a, b); }
double power(double a, long long b) {
  double x = 1;
  for (int i = 0; i < b; i++) {
    x = x * a;
  }
  return x;
}
int main() {
  long long a, b, n, low, high;
  cin >> a >> b >> n;
  vector<long long> fact;
  long long num = GCD(a, b);
  long long i;
  for (i = 1; i * i < num; i++) {
    if (num % i == 0) {
      fact.push_back(i);
      fact.push_back(num / i);
    }
  }
  if (i * i == num) fact.push_back(i);
  long long S = fact.size();
  sort(fact.begin(), fact.end());
  while (n--) {
    cin >> low >> high;
    long long l = 0;
    long long r = S - 1;
    long long ans = -1;
    while (l <= r) {
      long long mid = (l + r) / 2;
      if (fact[mid] >= low && fact[mid] <= high) {
        ans = fact[mid];
        l = mid + 1;
      } else if (fact[mid] < low) {
        l = mid + 1;
      } else {
        r = mid - 1;
      }
    }
    cout << ans << endl;
  }
  return 0;
}
