#include <bits/stdc++.h>
using namespace std;
int d[100005], low[100005], high[100005];
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
int main() {
  int a, b;
  scanf("%d%d", &a, &b);
  int c = gcd(a, b);
  int i = 0, j = 0;
  for (i = 2;; i++) {
    if (i * i > c) break;
    if (c % i == 0) {
      d[j++] = c / i;
      d[j++] = i;
    }
  }
  d[j++] = 1;
  d[j++] = c;
  sort(d, d + j);
  int n;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%d%d", &low[i], &high[i]);
  }
  for (i = 0; i < n; i++) {
    if (c < low[i])
      printf("-1\n");
    else {
      int l = 0, r = j;
      while (l + 1 < r) {
        int mid = (l + r) / 2;
        if (d[mid] > high[i]) {
          r = mid;
        } else {
          l = mid;
        }
      }
      if (d[l] >= low[i])
        printf("%d\n", d[l]);
      else
        printf("-1\n");
    }
  }
  return 0;
}
