import sys
input = sys.stdin.readline
from collections import *
from bisect import *

def lis(l):
    dp = [10**18]*(len(l)+1)
    dp[0] = -10**18
    res = [-1]*N
    
    for i in range(len(l)):
        j = bisect_left(dp, l[i])
        dp[j] = l[i]
        res[i] = bisect_left(dp, 10**18)-1
    
    return res

N = int(input())
A = list(map(int, input().split()))
ans = 0
res1 = lis(A)
A.reverse()
res2 = lis(A)
res2.reverse()
A.reverse()

for i in range(N):
    ans = max(ans, min(res1[i], res2[i])-1)

A = list(map(lambda x: -x, A))
res1 = lis(A)
A.reverse()
res2 = lis(A)
res2.reverse()
A.reverse()

for i in range(N):
    ans = max(ans, min(res1[i], res2[i])-1)

print(ans)