import sys


def input():
    return sys.stdin.readline()[:-1]

N = input()
a, b, c = map(int, input().split())

if c == a or c == b:
    print('No')
elif c < a and c < b and a < b:
    print('No')
elif c > a and c > b and a > b:
    print('No')
else:
    print('Yes')