import itertools

def is_valid(perm):
    for i in range(len(perm) - 2):
        a, b, c = perm[i], perm[i+1], perm[i+2]
        if a == b or b == c or a == c:
            return False
        if a >= c:
            return False
        is_max = b > a and b > c
        is_min = b < a and b < c
        if not (is_max or is_min):
            return False
    return True

D = list(map(int, input().split()))
found = False

# Generate all unique permutations
unique_perms = list(set(itertools.permutations(D)))

for perm in unique_perms:
    if is_valid(perm):
        found = True
        break

print("YES" if found else "NO")