#include #include using namespace std; using namespace atcoder; using ll = long long; using ld = long double; #define int ll #define OVERLOAD_REP(_1, _2, _3, name, ...) name #define REP2(i, l, r) for (int i = (int)(l); i < (int)(r); ++i) #define REP1(i, n) REP2(i, 0, n) #define rep(...) OVERLOAD_REP(__VA_ARGS__, REP2, REP1)(__VA_ARGS__) #define RREP2(i, r, l) for (int i = (int)(r)-1; i >= (int)(l); --i) #define RREP1(i, n) RREP2(i, n, 0) #define rrep(...) OVERLOAD_REP(__VA_ARGS__, RREP2, RREP1)(__VA_ARGS__) #define all(x) begin(x), end(x) #define rall(x) rbegin(x), rend(x) #define debug(x) cerr << #x << ": " << (x) << endl #define pb push_back #define mp make_pair #define mt make_tuple const int INF = 4e18; const int MOD = 998244353; const int MOD1 = 1e9 + 7; template inline bool chmax(T &a, T b) { return a < b ? a = b, 1 : 0; } template inline bool chmin(T &a, T b) { return a > b ? a = b, 1 : 0; } template T pow(T a, T b, T m) { return b ? b&1 ? a*pow(a, b^1, m)%m : pow(a*a%m, b>>1, m)%m : 1; } template T pow(T a, T b) { return b ? b&1 ? pow(a, b^1)*a : pow(a*a, b>>1) : 1; } template void input(T&... args) { ((cin >> args), ...); } template void print(T... args) { ((cout << args << " "), ...); } template void println(T... args) { print(args...); cout << endl; } template void println(vector A) { for (T a : A) print(a); cout << endl; } signed main() { ios::sync_with_stdio(false); cin.tie(nullptr); int N; input(N); vector> edges(N); rep(i, N) { int M; input(M); rep(j, M) { int A; input(A); edges[i].pb(A-1); } } vector visited(N, false); stack st; visited[0] = true; st.push(0); while (!st.empty()) { int i = st.top(); st.pop(); rep(j, edges[i].size()) { if (!visited[edges[i][j]]) { visited[edges[i][j]] = true; st.push(edges[i][j]); } } } bool ans = true; rep(i, N) ans &= visited[i]; println(ans ? "Yes" : "No"); }