#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    int n;
    cin >> n;
    int a[n][100];
    rep(i,n){
        rep(j,100){
            a[i][j] = -1;
        }
    }

    rep(i,n){
        int p; cin >> p;
        rep(j,p){
            cin >> a[i][j];
        }
    }
    int cnt = 0;
    rep(j,100){
        rep(i,n){
            if(a[i][j] != -1){
                if(cnt == 0){
                    cout << a[i][j];
                    cnt++;
                }else{
                    cout << ' ' << a[i][j];
                }
            }
        }
    }
    cout << endl;

    return 0;
}