#include <iostream>
#include <vector>
#include <queue>
using namespace std;

int main(){
    int n;
    cin >> n;
    vector<queue<int>> a(n);
    for(int i = 0; i < n; i++){
        int p;
        cin >> p;
        for(int j = 0; j < p; j++){
            int t;
            cin >> t;
            a[i].push(t);
        }
    }

    vector<int> ans;
    while(true){
        bool is_continue = false;
        for(int i = 0; i < n; i++){
            if(a[i].size()){
                ans.emplace_back(a[i].front());
                a[i].pop();
                is_continue = true;
            }
        }
        if(!is_continue) break;
    }
    for(int i = 0; i < ans.size(); i++){
        if(i != 0) cout << " ";
        cout << ans[i];
    }
    cout << endl;
    return 0;
}