// includes {{{ #include #include #include #include #include #include #include #include #include #include #include #include #include #include // #include // #include // #include // #include // }}} using namespace std; using ll = long long; // #undef DEBUG // #define DEBUG // DEBUG {{{ #include #include #include #include #include #include #include #include #include template < int n, class... T > typename std::enable_if< (n >= sizeof...(T)) >::type __output_tuple( std::ostream &, std::tuple< T... > const &) {} template < int n, class... T > typename std::enable_if< (n < sizeof...(T)) >::type __output_tuple( std::ostream &os, std::tuple< T... > const &t) { os << (n == 0 ? "" : ", ") << std::get< n >(t); __output_tuple< n + 1 >(os, t); } template < class... T > std::ostream &operator<<(std::ostream &os, std::tuple< T... > const &t) { os << "("; __output_tuple< 0 >(os, t); os << ")"; return os; } template < class T, class U > std::ostream &operator<<(std::ostream &os, std::pair< T, U > const &p) { os << "(" << p.first << ", " << p.second << ")"; return os; } template < class T > std::ostream &operator<<(std::ostream &os, const std::stack< T > &a) { os << "{"; for(auto tmp = a; tmp.size(); tmp.pop()) os << (a.size() == tmp.size() ? "" : ", ") << tmp.top(); os << "}"; return os; } template < class T, class Container, class Compare > std::ostream &operator<<(std::ostream &os, std::priority_queue< T, Container, Compare > a) { os << "{ (top) "; while(a.size()) os << a.top() << (a.size() == 1 ? "" : ", "), a.pop(); os << " }"; return os; } template < class T, class Container > std::ostream &operator<<(std::ostream &os, std::queue< T, Container > a) { os << "{ "; while(a.size()) os << a.front() << (a.size() == 1 ? "" : ", "), a.pop(); os << " }"; return os; } #ifdef DEBUG #if !defined(DEBUG_OUT) #define DEBUG_OUT std::cerr #endif #define dump(...) \ [&]() { \ auto __debug_tap = std::make_tuple(__VA_ARGS__); \ DEBUG_OUT << "[" << __LINE__ << "] " << #__VA_ARGS__ << " = " << __debug_tap \ << std::endl; \ }() template < class T > inline void dump2D(T &d, size_t sizey, size_t sizex) { for(size_t i = 0; i < sizey; i++) { DEBUG_OUT << "\t"; for(size_t j = 0; j < sizex; j++) DEBUG_OUT << d[i][j] << (j + 1 == sizex ? "" : "\t"); DEBUG_OUT << std::endl; } } template < class T > inline void dump1D(T &d, size_t sizey) { for(size_t i = 0; i < sizey; i++) { DEBUG_OUT << d[i] << (i + 1 == sizey ? "" : " "); } DEBUG_OUT << std::endl; } template < class T, class = typename std::iterator_traits< decltype(begin(T())) >::value_type, class = typename std::enable_if< !std::is_same< T, std::string >::value >::type > std::ostream &operator<<(std::ostream &os, const T &a) { os << "{"; for(auto ite = begin(a); ite != end(a); ++ite) os << (ite == begin(a) ? "" : ", ") << *ite; os << "}"; return os; } #else #define dump(...) ((void) 42) #define dump2D(...) ((void) 42) #define dump1D(...) ((void) 42) template < class T, class = typename std::iterator_traits< decltype(begin(T())) >::value_type, class = typename std::enable_if< !std::is_same< T, std::string >::value >::type > std::ostream &operator<<(std::ostream &os, const T &a) { for(auto ite = begin(a); ite != end(a); ++ite) os << (ite == begin(a) ? "" : " ") << *ite; return os; } #endif // }}} int main() { std::ios::sync_with_stdio(false), std::cin.tie(0); int n; cin >> n; vector> v(n); set valid; for(int i = 0; i < n; i++) { int k; cin >> k; if(k) { for(int j = 0; j < k; j++) { int a; cin >> a; v[i].push_back(a); } reverse(begin(v[i]), end(v[i])); valid.insert(i); } } vectorans; while(valid.size()) { auto vv = valid; vv.clear(); for(auto e : valid) { ans.push_back(v[e].back()); v[e].pop_back(); if(v[e].size()) vv.insert(e); } valid = vv; } cout << ans << endl; return 0; }