from collections import deque

N = int(input())
M, A = [], []
for _ in range(N):
    m, *a = map(lambda x: int(x)-1, input().split())
    M.append(m)
    A.append(a)

q = deque([0])
dist = [-1]*N
dist[0] = 0

while q:
    v = q.popleft()
    for u in A[v]:
        if dist[u] == -1:
            dist[u] = dist[v] + 1
            q.append(u)

if -1 in dist:
    print('No')
else:
    print('Yes')