#include <bits/stdc++.h>
using namespace std;
long long GCD(int a, int b) {
  if (b == 0) return a;
  return GCD(b, a % b);
}
vector<long long> getDevisors(int x) {
  vector<long long> ans;
  for (int i = 1; i * i <= x; i++) {
    if (x % i == 0) {
      ans.push_back(i);
      if (x / i != i) ans.push_back(x / i);
    }
  }
  return ans;
}
int main() {
  int a, b;
  scanf("%d%d", &a, &b);
  long long G = GCD(a, b);
  vector<long long> div = getDevisors(G);
  sort(div.begin(), div.end());
  int n;
  scanf("%d", &n);
  while (n--) {
    int F, L;
    scanf("%d%d", &F, &L);
    long long low = lower_bound(div.begin(), div.end(), F) - div.begin();
    long long high = lower_bound(div.begin(), div.end(), L) - div.begin();
    if (low >= div.size()) {
      cout << "-1\n";
      continue;
    }
    if (high >= div.size()) {
      high--;
    } else if (div[high] > L)
      high--;
    if (div[high] >= F && div[high] <= L)
      cout << div[high] << endl;
    else
      cout << "-1\n";
  }
}
