import typing
class SegmentTree:
	def __init__(
			self, 
			lis: list, 
			ele: typing.Any, 
			op: typing.Callable[[typing.Any, typing.Any], typing.Any]) -> None:
		self.n = len(lis)
		self.log = (self.n - 1).bit_length()
		self.size = 1 << self.log
		self.op = op
		self.ele = ele
		self.tree = self._build(lis)

	def _build(self, lis: list) -> list:
		res_tree = [self.ele] * (2 * self.size)
		for i, a in enumerate(lis):
			res_tree[self.size + i] = a
		for i in range(1, self.size)[::-1]:
			res_tree[i] = self.op(res_tree[2 * i], res_tree[2 * i + 1])
		return res_tree

	def __getitem__(self, i: int) -> None:
		return self.tree[self.size + i]

	def __setitem__(self, p: int, x: int) -> None:
		p += self.size
		self.tree[p] = x
		for i in range(1, self.log + 1):
			self.tree[p >> i] = self.op(self.tree[2 * (p >> i)], self.tree[2 * (p >> i) + 1])

	def prod(self, l: int, r: int) -> typing.Any:
		l += self.size
		r += self.size
		L = R = self.ele
		while l < r:
			if l & 1:
				L = self.op(L, self.tree[l])
				l += 1
			if r & 1:
				r -= 1
				R = self.op(self.tree[r], R)
			l >>= 1
			r >>= 1
		return self.op(L, R)

	def all_prod(self) -> typing.Any:
		return self.tree[1]

	def max_right(self, l: int, f: typing.Callable[[typing.Any], typing.Any]) -> int:
		if l == self.n:
			return self.n
		l += self.size
		sm = self.ele
		while True:
			while l % 2 == 0:
				l >>= 1
			if not f(self.op(sm, self.tree[l])):
				while l < self.size:
					l *= 2
					if f(self.op(sm, self.tree[l])):
						sm = self.op(sm, self.tree[l])
						l += 1
				return l - self.size
			sm = self.op(sm, self.tree[l])
			l += 1
			if (l & -l) == l:
				return self.n

def one_d_coordinate_compression(l: list) -> list:
	n = len(l)
	sorted_list = sorted(set(l))
	d = {sorted_list[i]: i for i in range(len(sorted_list))}
	return [d[i] for i in l]

n = int(input())
A = list(map(int, input().split()))
ST = SegmentTree([0] * (n + 10), 0, max)
def solve(a):
	l, r = [0] * n, [0] * n
	for i in range(n):
		l[i] = max(l[i], ST.prod(0, a[i]) + 1)
		ST[a[i]] = max(ST[a[i]], l[i])
	for i in range(n + 10): ST[i] = 0
	for i in range(n)[::-1]:
		r[i] = max(r[i], ST.prod(0, a[i]) + 1)
		ST[a[i]] = max(ST[a[i]], r[i])
	res = 0
	for i in range(n): res = max(res, min(l[i], r[i]) - 1)
	return res
ans = 0
ans = max(ans, solve(A))
A = [-i for i in A]
ans = max(ans, solve(A))
print(ans)