/* Problem URL: https://codeforces.com/contest/2205/problem/C */

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template <class T, class comp = less<>>
using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;

#define V vector

#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)

#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)

#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()

using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;

using ll = long long;

using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;

template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
    os << vec[0];
    for (size_t i = 1; i < vec.size(); i++) {
        os << ' ' << vec[i];
    }
    os << '\n';
    return os;
}

template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
    for (auto &i : vec) {
        is >> i;
    }
    return is;
}

template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
    for (auto &i : vec) {
        os << i[0];
        for (size_t j = 1; j < i.size(); j++) {
            os << ' ' << i[j];
        }
        os << '\n';
    }
    return os;
}

template<class v>
auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
    for (auto &i : vec) {
        for (auto &j : i) {
            is >> j;
        }
    }
    return is;
}

const int oo = INT32_MAX >> 1;
const ll OO = INT64_MAX >> 1;


void pre()
{

}

#define TEST 1

void solve()
{
    int n;
    cin >> n;

    vvi act(n);
    rep(i, n) {
        int m;
        cin >> m;
        act[i].resize(m);
        cin >> act[i];
    }

    V<bool> used(1e6 + 1);

    vi t(n);
    iota(all(t), 0);
    vi ans;
    while (true) {
        if (t.empty()) {
            break;
        }

        vi ch = t;
        vi tmp;
        while (ch.size() > 1) {
            int a = oo;
            repv(j, ch) {
                while (!act[j].empty() && used[act[j].back()]) {
                    act[j].pop_back();
                }

                if (act[j].empty()) {
                    a = oo;
                    break;
                }

                if (act[j].back() < a) {
                    tmp.clear();
                    tmp.push_back(j);
                    a = act[j].back();
                    continue;
                }

                if (act[j].back() == a) {
                    tmp.push_back(j);
                }
            }

            if (a == oo) {
                break;
            }

            used[a] = true;
            ans.push_back(a);
            swap(ch, tmp);
            tmp.clear();
        }

        bool rem = false;
        int cur = 0;
        rep(i, t.size()) {
            while (!act[t[i]].empty() && used[act[t[i]].back()]) {
                act[t[i]].pop_back();
            }

            if (act[t[i]].empty()) {
                rem = true;
                continue;
            }

            t[cur] = t[i];
            cur++;
        }
        while (t.size() > cur) {
            t.pop_back();
        }

        if (rem) {
            continue;
        }

        while (!act[ch[0]].empty()) {
            int j = act[ch[0]].back();
            act[ch[0]].pop_back();
            if (used[j]) {
                continue;
            }
            used[j] = true;
            ans.push_back(j);
        }
    }

    cout << ans;
}

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

    pre();

    int t;
    (TEST && cin >> t) || (t = 1);
    while (t--) {
        solve();
    }
}