#include <bits/stdc++.h>
using namespace std;
const int maxn = 6e5 + 1;
long long a, b;
int n;
long long gcd(long long a, long long b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
int main() {
  cin >> a >> b;
  ;
  long long val = gcd(a, b);
  vector<long long> gcdtbl;
  for (int i = 1; i * i <= val; i++) {
    if (val % i == 0) {
      gcdtbl.push_back(i);
      if (i * i != val) gcdtbl.push_back(val / i);
    }
  }
  sort(gcdtbl.begin(), gcdtbl.end());
  cin >> n;
  ;
  while (n--) {
    long long low, high;
    cin >> low >> high;
    ;
    int left = 0, right = gcdtbl.size() - 1;
    long long ans = -1;
    while (left <= right) {
      int mid = (left + right) / 2;
      if (gcdtbl[mid] >= low and gcdtbl[mid] <= high) {
        ans = gcdtbl[mid];
        left = mid + 1;
        continue;
      }
      if (gcdtbl[mid] <= low) {
        left = mid + 1;
      } else if (gcdtbl[mid] >= high) {
        right = mid - 1;
      }
    }
    cout << ans << endl;
  }
}
