import sys
from bisect import bisect_left, bisect_right
from collections import defaultdict, deque
from itertools import product
INF = int(1e18); arr4 = ((-1, 0), (0, -1), (1, 0), (0, 1))
def dmp(*args, sep=" ", end="\n"): print(*args, sep=sep, end=end, file=sys.stderr)
if "DEBUG" not in sys.argv: dmp = lambda *args: None
import pypyjit
sys.setrecursionlimit(10**7); pypyjit.set_param('max_unroll_recursion=0')

n = int(input())
g = [[] for _ in range(n)]
for i in range(n):
    m, *a = map(lambda x: int(x)-1, input().split())
    for x in a:
        g[i].append(x)
visited = [0] * n
def dfs(v):
    if visited[v]: return
    visited[v] = 1
    for nv in g[v]:
        dfs(nv)
dfs(0)
print('Yes' if sum(visited) == n else 'No')