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

void solve() {
    ll l, r;
    cin >> l >> r;

    ll k = (l + r) - (l + l) + 1;
    k %= 8;

    ll x = 0;
    for (ll i = 0; i < k; i++) {
        ll t = (l + r) - (k - 1 - i);
        if (i % 4 < 2) x ^= t;
    }
    cout << x << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t;
    cin >> t;

    while (t--) {
        solve();
    }

    return 0;
}