#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic pop
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

ll f(ll x) {
  ll res = 0;
  for(ll t = x / 4 * 4; t < x; t++) res ^= t;
  return res;
}

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int tt;
  cin >> tt;
  while(tt--) {
    ll l, r;
    cin >> l >> r;
    ll y = l + r + 1;
    ll ans = 0;
    for(ll x: {2 * l, 2 * l + 1}) {
      ll z = y - x;
      ll cnt = (z + 3) / 4;
      ans ^= (f(x >> 2) ^ f((x >> 2) + cnt)) << 2;
      if (cnt % 2) ans ^= x & 3;
    }
    cout << ans << '\n';
  }
}