#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,n) for(ll i=0;i<(n);++i)

main(){

  ll n;
  cin>>n;
  vector<ll> p(n);
  vector<vector<ll>> a(n);
  rep(i,n){
    cin>>p[i];
    a[i].resize(p[i]);
    rep(j,p[i])cin>>a[i][j];
  }

  vector<vector<ll>> x(*max_element(p.begin(),p.end()));
  rep(i,n){
    rep(j,p[i])x[j].emplace_back(a[i][j]);
  }

  for(auto& v:x)sort(v.begin(),v.end());

  for(auto y:x){
    for(auto x:y){
      cout<<x<<" ";
    }
  }
  cout<<endl;

}