#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;
#define DUMP(x)  cout << #x << " = " << (x) << endl;
#define FOR(i, m, n) for(ll i = m; i < n; i++)
#define IFOR(i, m, n) for(ll i = n - 1; i >= m; i-- )
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
#define FOREACH(x,a) for(auto& (x) : (a) )
#define ALL(v) (v).begin(), (v).end()
#define SZ(x) ll(x.size())

int main(){
  ll n; cin >> n;
  vector<deque<ll>> a(n);
  ll maxi = 0;
  REP(i,n){
    ll p; cin >> p;
    maxi = max(p,maxi);
    REP(j,p){
      ll b; cin >> b;
      a[i].push_back(b);
    }
  }
  vector<ll> ans;
  REP(j,maxi){
    REP(i,n) if(!a[i].empty()){
      ll b = a[i].front();
      a[i].pop_front();
      ans.push_back(b);
    }
  }

  REP(i,SZ(ans)){
    cout << ans[i] << " \n"[i==SZ(ans)-1];
  }
}