#include <bits/stdc++.h>
#define int long long
using namespace std;

void getFactors(vector<int>& factors, int n) {
	vector<pair<int, int>> primes;
	for (int i = 2, cnt; i <= n / i; i++) {
		for (cnt = 0; n % i == 0; n /= i, cnt++);
		if (cnt) primes.push_back({ i, cnt });
	}
	if (n != 1) primes.push_back({ n, 1 });
	factors.push_back(1);
	for (int i = 0, size = 1; i < primes.size(); i++, size = factors.size())
		for (int prd = primes[i].first; primes[i].second--; prd *= primes[i].first)
			for (int j = 0; j < size; j++)
				factors.push_back(factors[j] * prd);
}

signed main() {
	int x, y, q; cin >> x >> y >> q;
	vector<int> factors, v;
	getFactors(factors, x);
	for (int i = 0; i < factors.size(); i++)
		if (y % factors[i] == 0)
			v.push_back(factors[i]);
	sort(v.begin(), v.end());
	for (int l, r; q--;) {
		scanf("%lld %lld", &l, &r);
		auto it = upper_bound(v.begin(), v.end(), r);
		if (*(it - 1) >= l)
			cout << *(it - 1) << endl;
		else
			cout << "-1\n";
	}
	return 0;
}