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

int x,y,q,l,r;
map<int,int>a,b,mp;
vector<int>g,d;

void decompos_prime(int x,map<int,int>& mp){
	while(!(x & 1))
		x >>= 1, mp[2]++;
	for(int i = 3; i * i <= x; i += 2){
		while(x % i == 0)
			x /= i, mp[i]++;
	}
	if(x != 1)
		mp[x]++;
}

int main(){
	ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	
	cin >> x >> y >> q;
	
	decompos_prime(x,a);
	decompos_prime(y,b);
	for(auto& p : a){
		if(b.count(p.first))
			mp[p.first] = min(p.second,b[p.first]);
	}
	for(auto& p : mp){
		for(int i = 1; i <= p.second; i++)
			g.push_back(p.first);
	}
	int m = 1 << int(g.size());
	for(int i = 1; i <= m; i++){
		int ans = 1;
		for(int j = 0; j < int(g.size()); j++){
			if(i >> j & 1)
				ans *= g[j];
		}
		d.push_back(ans);
	}
	sort(d.begin(),d.end());
	
	while(q--){
		cin >> l >> r;
		
		auto it = lower_bound(d.begin(),d.end(),l);
		if(it == d.end() || *it > r)
			cout << "-1\n";
		else{
			int n = it - d.begin();
			while(d[n] <= r && n < int(d.size()))
				n++;
			cout << d[n-1] << '\n';
		}
	}
	
	return 0;
}