#include "bits/stdc++.h"
#define int long long
#define ull unsigned long long
#define double long double
#define PII pair<int,int>
#define TIII tuple<int,int,int>
#define LL __int128
#define eps 1e-6
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
constexpr int N = 2e5 + 10, M = 2e6 + 10, mod = 1e9 + 7, inf = 1e18;
int n, m;

void solve()
{
    //记录每行每列有哪些城堡和障碍
    unordered_map<int, vector<PII > > X, Y;
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        int x, y;
        cin >> x >> y;
        X[x].emplace_back(y, 1);
        Y[y].emplace_back(x, 1);
    }
    cin >> m;
    for (int i = 1; i <= m; i++)
    {
        int x, y;
        cin >> x >> y;
        X[x].emplace_back(y, 0);
        Y[y].emplace_back(x, 0);
    }
    //记录同一行/列能互相攻击到的两个列/行坐标
    vector<TIII > boy, girl;
    for (auto [x, vec]: X)
    {
        std::sort(vec.begin(), vec.end());
        for (int i = 1; i < vec.size(); i++)
        {
            //y1 < y2
            auto [y1, tag1] = vec[i - 1];
            auto [y2, tag2] = vec[i];
            if (tag1 && tag2)
            {
                if (y1 + 1 == y2) return (void) (cout << -1 << endl); //相邻无解
                boy.emplace_back(x, y1, y2);//位于x行的y1列 和 y2列能互相攻击
            }
        }
    }
    for (auto [y, vec]: Y)
    {
        std::sort(vec.begin(), vec.end());
        for (int i = 1; i < vec.size(); i++)
        {
            //x1 < x2
            auto [x1, tag1] = vec[i - 1];
            auto [x2, tag2] = vec[i];
            if (tag1 && tag2)
            {
                if (x1 + 1 == x2) return (void) (cout << -1 << endl); //相邻无解
                girl.emplace_back(y, x1, x2);//位于y列的x1行 和 x2行能互相攻击
            }
        }
    }
    vector adj(n, vector<int>());
    n = boy.size(), m = girl.size();
    //男孩选女孩
    for (auto u = 0; u < n; u++)
    {
        auto [x, y1, y2] = boy[u];
        for (auto v = 0; v < m; v++)
        {
            auto [y, x1, x2] = girl[v];
            //若位于十字中心 双倍收益
            if (x1 < x && x2 > x && y1 < y && y2 > y)
            {
                adj[u].emplace_back(v);
            }
        }
    }
    //跑最大匹配 即二分图的最小点覆盖
    vector<int> vis(m), npy(m, -1);
    function<bool(int)> dfs = [&](int u)
    {
        for (auto &v: adj[u])
        {
            if (vis[v]) continue;
            vis[v] = true;
            if (npy[v] == -1 || dfs(npy[v]))
            {
                npy[v] = u;
                return true;
            }
        }
        return false;
    };
    for (int u = 0; u < n; u++)
    {
        vector<int>(m).swap(vis);
        dfs(u);
    }
    vector<PII > ans;//记录
    vector<int> happy(n);//这个男孩有没有匹配到女朋友
    for (int v = 0; v < m; v++)
    {
        if (npy[v] != -1)
        {
            happy[npy[v]] = true;
            //男孩的行 女孩的列
            ans.emplace_back(get<0>(boy[npy[v]]), get<0>(girl[v]));
        }
        else
        {
            auto [y, x1, x2] = girl[v]; //独立美丽
            //放在中间即可
            ans.emplace_back(x1 + 1, y);
        }
    }
    for (int u = 0; u < n; u++)
    {
        if (!happy[u])
        {
            auto [x, y1, y2] = boy[u];
            ans.emplace_back(x, y1 + 1);
        }
    }
    cout << ans.size() << endl;
    for (auto [x, y]: ans)
    {
        cout << x << " " << y << endl;
    }
}

signed main()
{
    std::ios::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
    cout << fixed << setprecision(2);

    int Cases = 1;
    cin >> Cases;
    while (Cases--)
    {
        solve();
    }
    return 0;
}