#include <iostream>
#include <map>
#include <set>
#include <queue>
#include <cmath>
#include <vector>
#include <string>
#include <algorithm>
#include <functional>
using namespace std;
#pragma warning (disable: 4996)

int N, A[1 << 20];
int dp[1 << 20];
int cl[1 << 20], cr[1 << 20];
int dl[1 << 20], dr[1 << 20];

vector<int> solve(vector<int> vec) {
	int cnt = 0; vector<int> res;
	for (int i = 0; i < N; i++) dp[i] = 0;
	for (int i = 0; i < vec.size(); i++) {
		int pos1 = lower_bound(dp, dp + cnt, vec[i]) - dp;
		dp[pos1] = vec[i]; if (pos1 == cnt) cnt++;
		res.push_back(pos1 + 1);
	}
	return res;
}

int main() {
	cin >> N;
	for (int i = 1; i <= N; i++) cin >> A[i];

	vector<int> vec1, vec2;
	for (int i = 1; i <= N; i++) vec1.push_back(A[i]);
	vector<int> c1 = solve(vec1); reverse(vec1.begin(), vec1.end());
	vector<int> c2 = solve(vec1); reverse(c2.begin(), c2.end());
	for (int i = 1; i <= N; i++) vec2.push_back(-A[i]);
	vector<int> c3 = solve(vec2); reverse(vec2.begin(), vec2.end());
	vector<int> c4 = solve(vec2); reverse(c4.begin(), c4.end());

	for (int i = 1; i <= N; i++) cl[i] = c1[i - 1];
	for (int i = 1; i <= N; i++) cr[i] = c2[i - 1];
	for (int i = 1; i <= N; i++) dl[i] = c3[i - 1];
	for (int i = 1; i <= N; i++) dr[i] = c4[i - 1];

	int maxn = 0;
	for (int i = 1; i <= N; i++) {
		maxn = max(maxn, min(cl[i], cr[i]));
		maxn = max(maxn, min(dl[i], dr[i]));
	}
	cout << maxn - 1 << endl;
	return 0;
}