#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import array
import itertools


def is_inc_kado_seq(seq):
    cond0 = len(seq) == 3
    cond1 = len(set(seq)) == 3
    cond2 = seq[1] == max(seq) or seq[1] == min(seq)
    return cond0 and cond1 and cond2


def is_inc_kado_seq_seq(seq):
    n = len(seq)
    for i in range(n - 2):
        if not is_inc_kado_seq(seq[i: i + 3]):
            return False
    else:
        return True


def can_create_inc_kado_seq_seq(seq):
    for cand in itertools.permutations(seq):
        if is_inc_kado_seq_seq(cand):
            return True
    else:
        return False


def main():
    seq = array.array("B", map(int, input().split()))
    print("YES" if can_create_inc_kado_seq_seq(seq) else "NO")


if __name__ == '__main__':
    main()