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


int gcd(int a,int b) 
{
    while (b!=0) 
    {
        int temp=b;
        b=a%b;
        a=temp;
    }
    return a;
}


vector<int> f(int n) 
{
    vector<int> a;
    for (int i=1;i*i<=n;i++) 
    {
        if (n%i==0) 
        {
            a.push_back(i);
            if (i!=n/i) 
            {
                a.push_back(n/i);
            }
        }
    }
    sort(a.rbegin(),a.rend()); 
    return a;
}

int main()
 {
    int x,y;
    cin>>x>>y;
    
    
    int g=gcd(x,y);
    
   
    vector<int> a=f(g);
    
    int q;
    cin>>q;
    while (q--) 
    {

        int l,r;
        cin>>l>>r;
        
        
        bool flag=false;
        for (int d:a) 
        {
            if (d>=l&&d<=r) 
            {
                cout<<d<<endl;
                flag=true;
                break;
            }
        }
        if (!flag) 
        {
            cout<<-1<<endl;
        }
    }
    
    return 0;
}