#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    ll n;
    cin >> n;
    vector<queue<ll>> vq(n);
    ll cnt = 0;
    rep(i, n) {
        ll p;
        cin >> p;
        rep(ii, p) {
            ll a;
            cin >> a;
            vq[i].push(a);
        }
        cnt = max(cnt, p);
    }
    vector<ll> ans;
    rep(i, cnt) {
        rep(ii, n) {
            if (sz(vq[ii]) == 0) continue;
            ans.push_back(vq[ii].front());
            vq[ii].pop();
        }
    }
    rep(i, sz(ans)) {
        printf("%lld%s", ans[i], (i == (sz(ans) - 1)) ? "\n" : " ");
    }
    return 0;
}