#include <bits/stdc++.h>
using namespace std;
const long long Mod = 1000000007;
void div(int n, vector<int> &divisors) {
  for (int i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      divisors.push_back(i);
      int v = n / i;
      if (v * i == n && n % v == 0) divisors.push_back(v);
    }
  }
}
int main() {
  int n, m;
  scanf("%d %d", &n, &m);
  vector<int> divMin, divMax;
  div(min(n, m), divMin);
  div(max(n, m), divMax);
  sort(divMax.begin(), divMax.end());
  int q;
  scanf("%d", &q);
  while (q--) {
    int ans = 0;
    int low, high;
    scanf("%d %d", &low, &high);
    for (auto d : divMin) {
      if (d >= low && d <= high &&
          binary_search(divMax.begin(), divMax.end(), d)) {
        ans = max(ans, d);
      }
    }
    if (!ans)
      puts("-1");
    else
      printf("%d\n", ans);
  }
  return 0;
}
