#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int INF = 1e9 + 10;
const ll INFL = 4e18;

vector<int> topological_sort(const vector<vector<int>> &G) {
    int n = G.size();
    vector<int> indeg(n);
    for (int i = 0; i < n; i++) {
        for (int nxt : G[i]) {
            indeg[nxt]++;
        }
    }
    queue<int> Q;
    for (int i = 0; i < n; i++) {
        if (indeg[i] == 0) {
            Q.push(i);
        }
    }
    vector<int> ret;
    while (!Q.empty()) {
        int now = Q.front();
        Q.pop();
        for (int nxt : G[now]) {
            indeg[nxt]--;
            if (indeg[nxt] == 0) {
                Q.push(nxt);
            }
        }
        ret.push_back(now);
    }
    return ret;
}

int main() {
    int N;
    cin >> N;
    vector<vector<int>> G(N);
    for (int i = 0; i < N; i++) {
        int m;
        cin >> m;
        for (int j = 0; j < m; j++) {
            int a;
            cin >> a;
            a--;
            G[i].push_back(a);
        }
    }

    vector<int> tp = topological_sort(G);
    int start = tp.size() == N ? tp.front() : 0;

    queue<int> Q;
    Q.push(start);
    vector<bool> seen(N, false);
    seen[start] = true;

    while (!Q.empty()) {
        int now = Q.front();
        Q.pop();

        for (int nxt : G[now]) {
            if (!seen[nxt]) {
                seen[nxt] = true;
                Q.push(nxt);
            }
        }
    }

    bool ans = true;
    for (bool x : seen) {
        if (!x) {
            ans = false;
        }
    }

    if (ans) {
        cout << "Yes" << endl;
    } else {
        cout << "No" << endl;
    }
}