from itertools import permutations as perm
D = list(map(int, input().split()))

def check(a, b, c):
    if a == b or b == c or a == c:
        return False
    return max(a, b, c) == b or min(a, b, c) == b

for x in perm(D):
    if not (x[0]< x[2] < x[4] < x[6] and x[1] < x[3] < x[5]):
        continue
    for i in range(5):
        a, b, c = x[i:i+3]
        if not check(a, b, c):
            break
    else:
        print('YES')
        exit()
print('NO')