#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector< vector<int> > a(n);
    int maxp = 0;
    for (int i = 0; i < n; i++) {
        int p;
        cin >> p;
        maxp = max(maxp, p);
        a[i].resize(p);
        for (int j = 0; j < p; j++) {
            cin >> a[i][j];
        }
    }

    vector<int> ans;
    for (int j = 0; j < maxp; j++) {
        for (int i = 0; i < n; i++) {
            if (a[i].size() <= j) continue;
            ans.push_back(a[i][j]);
        }
    }

    int sz = ans.size();
    for (int i = 0; i < sz; i++) {
        cout << ans[i] << " \n"[i + 1 == sz];
    }
    return 0;
}