#include <fstream>
#include <set>
using namespace std;
ifstream fin("interclasari.in");
ofstream fout("interclasari.out");
set <int> binaryTree;
int i,j,n,m,nr;
int main()
{
    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>m;
        for(j=1;j<=m;j++)
        {
            fin>>nr;
            binaryTree.insert(nr);
        }
    }
    while(binaryTree.size()>1)
    {
        fout<<*binaryTree.begin()<<" ";
        binaryTree.erase(binaryTree.begin());
    }
    fout<<*binaryTree.begin();
    return 0;
}