import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

N = INT()
A = LIST()

def LIS(a):
    N = len(a)
    dp = [INF]*N
    size = [0]*N
    for i in range(N):
        idx = bisect_left(dp, a[i])
        dp[idx] = a[i]
        size[i] = idx+1
    return size

def LDS(a):
    return LIS([-x for x in a])

linc = LIS(A)
ldec = LDS(A)

A = A[::-1]

rinc = LDS(A)
rdec = LIS(A)

ans = 0

for i in range(N):
    ans = max(
        ans, 
        min(linc[i], rdec[N-1-i]),
        min(ldec[i], rinc[N-1-i])
        )
print(ans-1)