from bisect import bisect_left
INF = 10 ** 10
ans = 0
n = int(input())
a = list(map(int, input().split()))
ic = [0] * n
dc = [0] * n
dp = [INF] * (n + 1)
dp[0] = -INF
for i, x in enumerate(a):
    idx = bisect_left(dp, x)
    dp[idx] = x
    ic[i] = idx
dp = [INF] * (n + 1)
dp[0] = -INF
for i, x in enumerate(a[::-1]):
    idx = bisect_left(dp, x)
    dp[idx] = x
    dc[n - i - 1] = idx
for i in range(n):
    ans = max(ans, min(ic[i], dc[i]))
a = list(map(lambda x: -x, a))
ic = [0] * n
dc = [0] * n
dp = [INF] * (n + 1)
dp[0] = -INF
for i, x in enumerate(a):
    idx = bisect_left(dp, x)
    dp[idx] = x
    ic[i] = idx
dp = [INF] * (n + 1)
dp[0] = -INF
for i, x in enumerate(a[::-1]):
    idx = bisect_left(dp, x)
    dp[idx] = x
    dc[n - i - 1] = idx
for i in range(n):
    ans = max(ans, min(ic[i], dc[i]))
print(ans - 1)