// #define DEBUGGING
#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ALL(V) (V).begin(), (V).end()
#define ALLR(V) (V).rbegin(), (V).rend()

template <typename T> using V = vector<T>;
template <typename T> using VV = V<V<T>>;
using ll = int64_t;
using ull = uint64_t;
using PLL = pair<ll, ll>;

template <typename T> const T& var_min(const T &t) { return t; }
template <typename T> const T& var_max(const T &t) { return t; }
template <typename T, typename... Tail> const T& var_min(const T &t, const Tail&... tail) { return min(t, var_min(tail...)); }
template <typename T, typename... Tail> const T& var_max(const T &t, const Tail&... tail) { return max(t, var_max(tail...)); }
template <typename T, typename... Tail> void chmin(T &t, const Tail&... tail) { t = var_min(t, tail...); }
template <typename T, typename... Tail> void chmax(T &t, const Tail&... tail) { t = var_max(t, tail...); }
template <typename T> const T& clamp(const T &t, const T &low, const T &high) { return max(low, min(high, t)); }
template <typename T> void chclamp(T &t, const T &low, const T &high) { t = clamp(t, low, high); }

namespace init__ {

struct InitIO {
    InitIO() {
        cin.tie(nullptr);
        ios_base::sync_with_stdio(false);
        cout << fixed << setprecision(30);
    }
} init_io;

}

#ifdef DEBUGGING
// #include "../debug/debug.cpp"
#include "../../debug/debug.cpp"
#else
#define DEBUG(...) 0
#define DEBUG_SEPARATOR_LINE 0
#endif

template <typename T>
T make_v(T init) { return init; }

template <typename T, typename... Tail>
auto make_v(T init, size_t s, Tail... tail) {
#define rec make_v(init, tail...)
    return V<decltype(rec)>(s, rec);
#undef rec
}

int main() {
    ll N;
    cin >> N;
    V<queue<ll>> vq;
    while(N--) {
        ll p;
        cin >> p;
        queue<ll> que;
        while(p--) {
            ll a;
            cin >> a;
            que.push(a);
        }
        if(que.size()) vq.push_back(move(que));
    }

    V<ll> ans;
    while(vq.size()) {
        V<queue<ll>> nxt_vq;
        for(auto &&que : vq) {
            ans.push_back(que.front());
            que.pop();
            if(que.size()) nxt_vq.push_back(move(que));
        }
        DEBUG(nxt_vq.size());
        vq = move(nxt_vq);
    }
    for(ll i = 0; i < ans.size(); i++) cout << ans[i] << " \n"[i + 1 == ans.size()];
    return 0;
}