from itertools import *

def kadomatsu(a, b, c):
    if a <= c:
        return False
    for i in [-1, 1]:
        if a * i < b * i and b * i > c * i and a != c:
            return True
    return False

D = list(map(int, input().split()))
ans = "NO"
for tup in permutations(D):
    for i in range(5):
        if not kadomatsu(tup[i], tup[i + 1], tup[i + 2]):
            break
    else:
        ans = "YES"
print(ans)