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

typedef long long ll;



struct Base {
    ll d[70];
    Base() {
        for (int i=0; i<=60; i++) d[i] = 0;
    }

    ll& operator[](int i) {return d[i];}

    bool add(ll x) {
        for (int i=60; i>=0; i--) if (x&(1ll<<i)) {
            if (d[i]) {
                x ^= d[i];
            }
            else {
                d[i] = x;
                return true;
            }
        }
        return false;
    }
};



void solve()
{
    int n, m;
    scanf("%d%d", &n, &m);
    vector<ll> orig_a(n);
    vector<ll> orig_b(m);
    Base base_a, base_b;
    
    ll X = 0;
    for (ll i=0, x, y; i<n; i++) {
        scanf("%lld%lld", &x, &y);
        orig_a[i] = x^y;
        X ^= x;
        base_a.add(orig_a[i]);
    }
    for (ll i=0, x, y; i<m; i++) {
        scanf("%lld%lld", &x, &y);
        orig_b[i] = x^y;
        X ^= x;
        base_b.add(orig_b[i]);
    }


    for (int i=60; i>=0; i--) {
        if (base_a[i]==0 && base_b[i]==0) {
            continue;
        }
        else if (base_b[i]==0) {
            if ((X&(1ll<<i)) == 0) {
                X ^= base_a[i];
            }
        }
        else if (base_a[i]==0) {
            if (X&(1ll<<i)) {
                X ^= base_b[i];
            }
        }
        else {
            if (X&(1ll<<i)) {
                X ^= base_a[i];
            }
            base_a.add(base_a[i]^base_b[i]);
        }
    }

    printf("%lld\n", X);

}



int main()
{
    int ttt;
    scanf("%d", &ttt);
    while (ttt--) {
        solve();
    }
    return 0;
}