import itertools as itr

def isIncreasingKadomatsu(a):
    # if a[0] == a[1] or a[0] == a[2] or a[1] == a[2]:
    #     return False
    # if (a[1] - a[0]) * (a[1] - a[2]) < 0:
    #     return False
    # if a[0] > a[2]:
    #     return False
    # return True

    if (a[0] != a[1] and a[1] != a[2] and a[2] != a[0]) and (a[1] == min(a) or a[1] == max(a)) and a[0] < a[2]:
        return True
    return False


def main():
    a = list(map(int, input().split()))

    for perm in itr.permutations(a, len(a)):
        for i in range(len(a) - 2):
            if not isIncreasingKadomatsu(perm[i : i + 3]):
                break
        else:
            print("YES")
            exit()

    print("NO")

if __name__ == '__main__':
    main()