#include <fstream>
#include <algorithm>
#include <queue>

using namespace std;

ifstream cin ("interclasari.in");
ofstream cout ("interclasari.out");

priority_queue<int, vector<int>,greater<int>>pq;

int q,n,x;

int main()
{
    cin>>q;
    while(q--)
    {
        cin>>n;
        for(int i=1;i<=n;i++)
        {
            cin>>x;
            pq.push(x);
        }
    }
    while(!pq.empty())
    {
        cout<<pq.top()<<' ';
        pq.pop();
    }
    return 0;
}