import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def is_kadomatu(a):
    return a[0] != a[2] and (a[0] - a[1])*(a[2] - a[1]) > 0

def solve():
    Ds = [int(i) for i in input().split()]

    for line in permutations(Ds):
        for i in range(7 - 2):
            if not is_kadomatu((line[i], line[i + 1], line[i + 2])):
                break
        else:
            print('YES')
            return

    print('NO')

if __name__ == '__main__':
    solve()