from bisect import bisect_left

n = int(input())
A = list(map(int, input().split()))
ans = 0
for _ in range(2):
    left = [-1] * n
    lst = []
    for i, a in enumerate(A):
        p = bisect_left(lst, a)
        left[i] = p
        if len(lst) == p:
            lst.append(a)
        else:
            lst[p] = a
            
    right = [-1] * n
    lst = []
    for i in range(n - 1, -1, -1):
        a = A[i]
        p = bisect_left(lst, a)
        right[i] = p
        if len(lst) == p:
            lst.append(a)
        else:
            lst[p] = a
            
    for l, r in zip(left, right):
        ans = max(ans, min(l, r))
    A = [-a for a in A]
print(ans)