from collections import deque
N=int(input())
G=[[] for _ in range(N*2)]

for i in range(N):
    MA=list(map(int,input().split()))
    if len(MA)==1:continue
    for j in range(1,len(MA)):
        v=i
        u=MA[j]-1
        G[v].append(u)
        G[v+N].append(u+N)

Q=deque()
vis=[False for _ in range(N*2)]
vis[0]=True
Q.append(0)

while len(Q):
    pos=Q.popleft()
    for nxt in G[pos]:
        if not vis[nxt]:
            vis[nxt]=True
            Q.append(nxt)
            continue
        if nxt+N<N and not vis[nxt+N]:
            vis[nxt+N]=True
            Q.append(nxt+N)
            continue
        if nxt-N>=0 and not vis[nxt-N]:
            vis[nxt+N]=True
            Q.append(nxt+N)

for i in range(N):
    if not vis[i] and not vis[i+N]:
        print("No")
        exit(0)
print("Yes")