#include <iostream>

using namespace std;
typedef long long ll;
int main(){
    int t; cin >> t;
    while(t){
        t--;
        ll l,r; cin >> l >> r;
        ll le = 2*l + (r + 1 - l)/8*8,ri = (l + r + 1);
        ll ans = 0;
        int j = 0;
        for(ll i=le;i<ri;i++){
            if(j%4<2) ans ^= i;
            j++;
        }
        cout << ans << "\n";
    }
}