#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <string>
#include <cstring>
#include <cmath>
#include <vector>

using namespace std;

int main(void)
{
	int n;
	cin>>n;
	int l, x, c = 0;
	vector<int> niz(1000);
	for(int i = 0; i < n; i++){
		cin>>l;
		for(int j = 0; j < l; j++){
			cin>>x;	
			niz.push_back(x);
		}	
	}
	sort(niz.begin(), niz.end());
	for(int i = 0; i < niz.size(); i++) if(niz[i] != 0)cout<<niz[i]<<" ";
    
     return 0;
}