from itertools import permutations as perm
def iskadomatsu(a,b,c):
	return a != c and (a > b and c > b or b > a and b > c)
D = map(int,raw_input().split())
for P in perm(D,7):
	if all(iskadomatsu(*P[i:i+3]) for i in xrange(5)):
		print "YES"
		break
else:
	print "NO"