from collections import defaultdict

N = int(input())
adj = defaultdict(list)
for i in range(N):
    M, *A = list(map(int, input().split()))
    for a in A:
        adj[i].append(a-1)


def dfs(v, used):
    if used[v]: return
    used[v] = True

    for to in adj[v]:
        dfs(to, used)


used = [False] * N
dfs(0, used)
if sum(used) == N:
    print('Yes')
else:
    print('No')