#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
using namespace std;


int main()
{
    int n, max1=0;
    cin >> n;
    vector<vector<int>> v(n);
    for (int i = 0; i < n; i++){
        int t;
        cin >> t;
        max1 = max(max1, t);
        for (int j = 0; j < t; j++){
            int c;
            cin >> c;
            v[i].push_back(c);
        } 
    }
    for (int i = 0; i < max1; i++){
        for (int j = 0; j < n; j++){
            if (!v[j].empty()){
                if (i != 0 || j != 0) cout << " ";
                cout << v[j][0];
                v[j].erase(v[j].begin());
            }
        } 
    }
    cout << endl;
}