#include #define loop(n) for (int ngtkana_is_genius = 0; ngtkana_is_genius < int(n); ngtkana_is_genius++) #define rep(i, begin, end) for(int i = int(begin); i < int(end); i++) #define all(v) v.begin(), v.end() #define rand(l, r) std::uniform_int_distribution<>(l, r)(mt) #define lint long long auto cmn = [](auto& a, auto b){if (a > b) {a = b; return true;} return false;}; auto cmx = [](auto& a, auto b){if (a < b) {a = b; return true;} return false;}; void debug_impl() { std::cerr << std::endl; } template void debug_impl(Head head, Tail... tail){ std::cerr << " " << head; debug_impl(tail...); } #ifndef STOPIT #define debug(...)\ std::cerr << std::boolalpha << "[" << #__VA_ARGS__ << "]:";\ debug_impl(__VA_ARGS__);\ std::cerr << std::noboolalpha; #else #define debug 0; #endif template auto make_vector_impl(size_t sz, T t) {return std::vector(sz, t);} template = nullptr> auto make_vector(size_t sz, U u) {return make_vector_impl(sz, T(u));} template = nullptr> auto make_vector(size_t sz) {return std::vector(sz);} template = nullptr> auto make_vector(size_t a, Args... args) {return make_vector_impl(a, make_vector(args...));} template auto& at(T& t, Size_t i) {return t.at(i);} template auto& at(T& t, Size_t i, Args... args) {return at(t.at(i), args...);} template < typename Container, typename Value = typename Container::value_type, std::enable_if_t::value, std::nullptr_t> = nullptr> std::istream& operator>> (std::istream& is, Container& v) { for (auto & x : v) { is >> x; } return is; } template < typename Container, typename Value = typename Container::value_type, std::enable_if_t::value, std::nullptr_t> = nullptr > std::ostream& operator<< (std::ostream& os, Container const& v) { os << "{"; for (auto it = v.begin(); it != v.end(); it++) {os << (it != v.begin() ? "," : "") << *it;} return os << "}"; } int main() { std::cin.tie(0); std::cin.sync_with_stdio(false); int n; std::cin >> n; auto a = make_vector< 2, int >(n, 0); rep(i, 0, n) { int p; std::cin >> p; auto & crr = a.at(i); crr.resize(p); rep(j, 0, p) { int x; std::cin >> x; crr.at(j) = x; } std::reverse(all(crr)); } // debug(a); std::vector< int > ret{}; while (true) { auto flag = false; rep(i, 0, n) { auto & crr = a.at(i); if (crr.empty()) { continue; } flag = true; ret.emplace_back(crr.back()); crr.pop_back(); } if (!flag) { break; } } int N = ret.size(); rep(i, 0, N) { std::cout << (i > 0 ? " " : "") << ret.at(i); } std::cout << std::endl; return 0; }