from scipy.sparse.csgraph import connected_components
from scipy.sparse import csr_matrix

N = int(input())
node = set()
RC = [tuple(map(int, input().split())) for _ in range(N)]
for r0, c0, r1, c1 in RC:
    node.add((r0, c0))
    node.add((r1, c1))
node_d = {rc: i for i, rc in enumerate(node)}

size = len(node_d)
frm, to = [], []
for r0, c0, r1, c1 in RC:
    frm.append(node_d[(r0, c0)])
    to.append(node_d[(r1, c1)])
matr = csr_matrix(([1] * N, (frm, to)), shape=(size, size))
p, labels = connected_components(matr)

conn_node = [0] * p
conn_edge = [0] * p

for x in labels:
    conn_node[x] += 1
for r0, c0, _, _ in RC:
    conn_edge[labels[node_d[(r0, c0)]]] += 1

for n,e in zip(conn_node, conn_edge):
    if n < e:
        print('NO')
        exit()
print('YES')