#include <iostream>
#include <vector>
#include <queue>

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

    std::vector<std::queue<int>> ques(n);
    for (auto& que : ques) {
        int m;
        std::cin >> m;

        while (m--) {
            int x;
            std::cin >> x;
            que.push(x);
        }
    }

    bool update = true;
    while (update) {
        update = false;

        for (auto& que : ques) {
            if (que.empty()) continue;

            update = true;
            std::cout << que.front() << " ";
            que.pop();
        }
    }

    std::cout << std::endl;
}

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

    solve();

    return 0;
}