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

int q,x,y,l,r,num,result[114514],k;
int gcd(int a,int b) {
	if (b==0) return a;
	return gcd(b,a%b);
}
void breakdown(int N){
	result[k++]=1;
	for (int i=2;i<=N;i++) {
		if (N%i==0){
	    	result[k++]=i;
    	}
	}
}
int main(){
	cin>>x>>y;
	cin>>q;
	num=gcd(x,y);
	breakdown(num);
	//for (int i=0;i<k;i++)  cout<<result[i]<<" ";
	while (q--){
		cin>>l>>r;
		int flag=0;
		for (int i=k-1;i>=0;i--){
			if (result[i]>=l && result[i]<=r){
				flag=1;
				cout<<result[i]<<"\n";
				break;
			}
		}
		if (!flag)  cout<<-1<<"\n";
	}
	return 0;
}