func main()
	var n: int :: cui@inputInt()
	var a: []int :: #[n]int
	for i(0, n - 1)
		do a[i] :: cui@inputInt()
	end for
	
	var ans: int :: solve(a)
	for i(0, n - 1)
		do a[i] :: -1 * a[i]
	end for
	do ans :: lib@max(ans, solve(a))
	do cui@print("\{ans}\n")
	
	func solve(a: []int): int
		var lis: []int :: getLisArr(a)
		do a.reverse()
		var revLis: []int :: getLisArr(a)
		do revLis.reverse()
		do a.reverse()
		var res: int :: 0
		for i(0, ^a - 1)
			do res :: lib@max(res, lib@min(lis[i], revLis[i]) - 1)
		end for
		ret res
		
		func getLisArr(a: []int): []int
			const infInt: int :: lib@intMax
			var n: int :: ^a
			var buff: []int :: [infInt].repeat(n + 1)
			var lisArr: []int :: #[n]int
			for i(0, n - 1)
				var idx: int :: f(buff, a[i])
				do buff[idx] :: a[i]
				do lisArr[i] :: f(buff, infInt)
				
				func f(arr: []int, val: int): int
					var ok: int :: -1
					var ng: int :: ^arr - 1
					while((ok - ng).abs() > 1)
						var mid: int :: (ok + ng) / 2
						if(val > arr[mid])
							do ok :: mid
						else
							do ng :: mid
						end if
					end while
					ret ok + 1
				end func
			end for
			ret lisArr
		end func
	end func
end func