class UnionFind():
	def __init__(self, n):
		self.par = [-1] * n
		self.rank = [0] * n
		self.siz = [1] * n

	def root(self, x):
		if self.par[x] == -1: return x
		else:
			self.par[x] = self.root(self.par[x])
			return self.par[x]

	def issame(self, x, y):
		return self.root(x) == self.root(y)

	def unite(self, x, y):
		rx = self.root(x)
		ry = self.root(y)
		if rx == ry: return False

		if self.rank[rx] < self.rank[ry]:
			rx, ry = ry, rx
		self.par[ry] = rx
		if self.rank[rx] == self.rank[ry]:
			self.rank[rx] += 1
		self.siz[rx] += self.siz[ry]
		return True

	def size(self, x):
		return self.siz[self.root(x)]

N = int(input())
uf = UnionFind(N)
for i in range(N):
	M, *A = map(int, input().split())
	for j in range(M):
		uf.unite(i, A[j]-1)
print("Yes" if uf.size(0) == N else "No")