#!/usr/bin/env python3
import functools
import operator

N = int(input())
a = [int(x) for x in input().split()]
if functools.reduce(operator.mul, [a[j] - a[i] for i in range(len(a)) for j in range(i + 1, len(a))]) > 0:
    print("Yes")
else:
    print("No")