#include <bits/stdc++.h>
using std::cin;
using std::cout;

const int N = 200054;

int n;
int a[N], D[N], f[N], g[N];

inline void up(int &x, const int y) {x < y ? x = y : 0;}

void LIS(int *f) {
	int i, L = 0;
	for (i = 1; i <= n; ++i)
		f[i] = std::upper_bound(D + 1, D + (L + 1), i, [] (const int x, const int y) {return a[x] < a[y];}) - D,
		up(L, f[i]), D[f[i]] = i;
}

int main() {
	int i, x, ans = 0;
	std::ios::sync_with_stdio(false), cin.tie(NULL);
	cin >> n;
	for (i = 1; i <= n; ++i) cin >> x, a[x] = i;
	LIS(f);
	std::reverse(a + 1, a + (n + 1));
	LIS(g);
	for (i = 1; i <= n; ++i) up(ans, f[i] + g[n - i + 1]);
	cout << --ans << '\n';
	return 0;
}