#include<algorithm>
#include<set>
#include<vector>
#include<string>
#include<stdlib.h>
#include<math.h>
#include<stdio.h>
#include<map>
#include<iostream>
using namespace std;
set<long long> s;
int main()
{
	long long a, b;
	cin >> a >> b;
	long long x = max(a, b);
	long long y = min(a, b);
	for (long long i = 1; i*i <= x; i++)
	{
		if ((x%i == 0)&&(y%i==0))
		{
			s.insert(i);
		}
		if ((y % (x / i) == 0)&&(x%i==0))
		{
			s.insert(x / i);
		}
	}
	long long jmin, jmax;
	long long e = -1;
	long long k;
	cin >> k;
	for (int i = 0; i < k; i++)
	{
		cin >> jmin >> jmax;
		auto it = s.end();
		it--;
		while (*it > jmax)
		{
			it--;
		}
		if ((*it >= jmin) && (*it <= jmax))
		{
			e = *it;
		}
		cout << e << endl;
		e = -1;
	}
}