#include using namespace std; typedef long long ll; typedef pair 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> a(n); REP(i,n){ ll p; cin >> p; REP(j,p){ ll b; cin >> b; a[i].push_back(b); } } vector ans; REP(j,n){ 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]; } }