#include <bits/stdc++.h>
using namespace std;
int main(void)
{
    int n, num, mx = 0;
    bool flag = 1;
    cin >> n;
    vector<queue<int>> q(n);
    for (int i = 0; i < n; i++) {
        int temp;
        cin >> num;
        mx = max(mx, num);
        for (int j = 0; j < num; j++) {
            cin >> temp;
            q[i].push(temp);
        }
    }
    while (mx--) {
        for (int i = 0; i < n; i++) {
            if (!(q[i].empty())) {
                int temp = q[i].front();
                q[i].pop();
                cout << temp << (mx != 0 ? " " : "");
            }
        }
    }
    cout << endl;
    return 0;
}