#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
vector<int> lis_vector(vector<int> arr) {
	int N = arr.size();
	vector<int> val(N, 1 << 30);
	vector<int> dp(N + 1);
	for (int i = 0; i < N; ++i) {
		*lower_bound(val.begin(), val.end(), arr[i]) = arr[i];
		dp[i + 1] = lower_bound(val.begin(), val.end(), 1 << 30) - val.begin();
	}
	return dp;
}
int main() {
	int N;
	cin >> N;
	vector<int> A(N);
	for (int i = 0; i < N; ++i) {
		cin >> A[i];
	}
	int ans = 0;
	for (int i = 0; i < 2; ++i) {
		vector<int> dpl = lis_vector(A);
		reverse(A.begin(), A.end());
		vector<int> dpr = lis_vector(A);
		reverse(dpr.begin(), dpr.end());
		reverse(A.begin(), A.end());
		for (int j = 0; j < N; ++j) {
			ans = max(ans, min(dpl[j + 1], dpr[j]) - 1);
			A[j] *= -1;
		}
	}
	cout << ans << endl;
	return 0;
}