#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
struct basis {
    ll p[100];
    void clear() { memset(p, 0, sizeof p); }
    void insert(ll x) {
        for (int i = 60; i >= 0; i--) {
            if (x >> i & 1) {
                if (p[i]) x ^= p[i];
                else {
                    p[i] = x;
                    break;
                }
            }
        }
    }
    ll query_max(ll x) {
        for (int i = 60; i >= 0; i--)
            if (!(x >> i & 1)) x ^= p[i];
        return x;
    }
    ll query_min(ll x) {
        for (int i = 60; i >= 0; i--)
            if (x >> i & 1) x ^= p[i];
        return x;
    }
} L;
int T, n, m;
ll a[10010];
int main() {
    scanf("%d", &T);
    while (T--) {
        scanf("%d%d", &n, &m);
        ll ans = 0;
        for (int i = 1; i <= n; i++) {
            ll x, y;
            scanf("%lld%lld", &x, &y);
            ans ^= x;
            a[i] = x ^ y;
        }
        L.clear();
        for (int i = 1; i <= m; i++) {
            ll x, y;
            scanf("%lld%lld", &x, &y);
            ans ^= x;
            L.insert(x ^ y);
        }
        ans = L.query_min(ans);
        for (int i = 1; i <= n; i++) {
            a[i] = L.query_min(a[i]);
        }
        L.clear();
        for (int i = 1; i <= n; i++) L.insert(a[i]);
        cout << L.query_max(ans) << endl;
    }
}