#include<bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  vector<vector<int>> E(N);
  for (int i = 0; i < N; i++) {
    int M;
    cin >> M;
    for (int j = 0; j < M; j++) {
      int A;
      cin >> A;
      A--;
      E[i].push_back(A);
    }
  }
  auto dfs = [&] (auto dfs, vector<bool> &used, int v, int cnt) -> void {
    if (cnt == N) {
      cout << "Yes" << endl;
      exit(0);
    }
    for (int w : E[v]) {
      if (!used[w]) {
        used[w] = true;
        cnt++;
        dfs(dfs, used, w, cnt);
        cnt--;
        used[w] = false;
      }
    }
  };
  vector<bool> used(N, false);
  used[0] = 1;
  int cnt = 1;
  dfs(dfs, used, 0, cnt);
  cout << "No" << endl;
}