n = input()
m = [map(int, raw_input().split()) for _ in xrange(n)]

B = {}
P = {}
for i in xrange(0, 111):
    for j in xrange(0, 111):
        B[(i, j)] = 0
        P[(i, j)] = 0

for a, b, c, d in m:
    if a == c:
        B[(a, b)] += 1
        B[(a-1, b)] += 1
    else:
        B[(a, b)] += 1
        B[(a, b-1)] += 1
    P[(a, b)] += 1
    P[(c, d)] += 1

for k, v in B.items():
    if v != 4:
        continue
    a, b = k
    if P[(a, b)] >= 3 or P[(a, b+1)] >= 3 or P[(a+1, b)] >= 3 or P[(a+1, b+1)] >= 3:
        print "NO"
        exit()
print "YES"