#include <bits/stdc++.h>

using namespace std;
typedef int ll;

void input(ll &n, ll &m, vector<vector<ll>> &clubs) {
    cin >> n >> m;
    clubs.resize(m);
    for (ll i = 0; i < m; i++) {
        ll s;
        cin >> s;
        clubs[i].resize(s);
        for (ll j = 0; j < s; j++) {
            cin >> clubs[i][j];
            clubs[i][j]--;
        }
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    ll T;
    cin >> T;
    while (T--) {
        ll n, m;
        vector<vector<ll>> clubs;
        input(n, m, clubs);

        if (m == 1) {
            if (n == 1)
                cout << "1\n";
            else if (n == 2)
                cout << "2\n";
            else
                cout << "-1\n";
        }
    }
}