#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <cmath>
#include <queue>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef string str;

#define ALL(x) (x).begin(),(x).end()
#define RALL(x) (x).rbegin(),(x).rend()
#define MAX_LL (1LL<<62)
#define MOD 998244353

ll max(const ll &a, const ll &b) {if(a>b) return a; else return b;}
ll min(const ll &a, const ll &b) {if(a<b) return a; else return b;}
ll calc_gcd(ll a, ll b) {while(true){if(a*b == 0) return a+b; else if(a>b) a %= b; else b %= a;}}
ull pow_mod(ull a, ull b, ull mod=-1) {if(mod<2) return 0; ull ans=1, now=a; while(b>0){if(b%2) ans=(ans*now)%mod; now=(now*now)%mod; b/=2;} return ans;}

bool update_max(ll &a, const ll &b) {if(a<b){a=b; return true;} else return false;}
bool update_max(ld &a, const ld &b) {if(a<b){a=b; return true;} else return false;}
bool update_min(ll &a, const ll &b) {if(a>b){a=b; return true;} else return false;}
bool update_min(ld &a, const ld &b) {if(a>b){a=b; return true;} else return false;}

ll upper_char_to_ll(const char &c) {return ll(c)-65;}

int main() {
  ll N;
  cin >> N;

  vector<vector<ll>> A(N);

  ll espar = 0;
  
  for(ll i=0; i<N; i++){
    ll M; cin >> M;
    if(M == 0)
      espar++;
    for(ll j=0; j<M; j++){
      ll temp; cin >> temp; A[i].push_back(temp-1);
    }
  }

  if(espar>=2){
    cout << "No" << endl;
    return 0;
  }
  
  vector<bool> is_reached(N);
  ll reached_counter = 0;
  queue<ll> reached_queue;

  reached_queue.push(0);
  is_reached[0] = true;
  reached_counter++;

  while(!reached_queue.empty()){
    ll next_sacrifice = reached_queue.front();
    //cout << next_sacrifice << ": " << endl;
    reached_queue.pop();
    for(ll i=0; i<A[next_sacrifice].size(); i++){
      if(is_reached[A[next_sacrifice][i]])
        continue;

      //cout << A[next_sacrifice][i] << " ";

      reached_queue.push(A[next_sacrifice][i]);
      is_reached[A[next_sacrifice][i]] = true;
      reached_counter++;
    }
    //cout << endl;
  }

  if(reached_counter >= N)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}