INF = float("INF")
N = int(input())
G = [[] for _ in range(N)]
for v in range(N):
   M, *A = map(int, input().split())
   G[v] = [a-1 for a in A]


def bfs(G, s):
   from collections import deque
   N = len(G)
   dist = [INF]*N
   Q = deque([s])
   dist[s] = 0
   while Q:
      v = Q.popleft()
      for a in G[v]:
         if dist[a] != INF:
            continue
         Q.append(a)
         dist[a] = dist[v] + 1
   return dist


dist = bfs(G, s=0)
ans = all(d != INF for d in dist)

if ans is True:
   print("Yes")
else:
   print("No")