/************************************************

* Author        :Running_Time

* Created Time  :2015-8-5 21:38:32

* File Name     :UVA_10534.cpp

 ************************************************/

#include <cstdio>

#include <algorithm>

#include <iostream>

#include <sstream>

#include <cstring>

#include <cmath>

#include <string>

#include <vector>

#include <queue>

#include <deque>

#include <stack>

#include <list>

#include <map>

#include <set>

#include <bitset>

#include <cstdlib>

#include <ctime>

using namespace std;

#define lson l, mid, rt << 1

#define rson mid + 1, r, rt << 1 | 1

typedef long long ll;

const int MAXN = 1e4 + 10;

const int INF = 0x3f3f3f3f;

const int MOD = 1e9 + 7;

int a[MAXN];

int d[MAXN];

int dp[MAXN], dp2[MAXN];

int main(void)    {     //UVA 10534 Wavio Sequence

    int n;

    while (scanf ("%d", &n) == 1)   {

        for (int i=1; i<=n; ++i)    scanf ("%d", &a[i]);

        memset (d, 0, sizeof (d));

        memset (dp, 0, sizeof (dp));

        memset (dp2, 0, sizeof (dp2));

        d[1] = a[1];    int len = 1;    dp[1] = 1;

        for (int i=2; i<=n; ++i)    {

            if (d[len] < a[i])  d[++len] = a[i];

            else    {

                int j = lower_bound (d+1, d+1+len, a[i]) - d;

                d[j] = a[i];

            }

            dp[i] = len;

        }

        d[1] = a[n];    int len2 = 1;   dp2[n] = 1;

        for (int i=n-1; i>=1; --i)    {

            if (d[len2] < a[i]) d[++len2] = a[i];

            else    {

                int j = lower_bound (d+1, d+1+len2, a[i]) - d;

                d[j] = a[i];

            }

            dp2[i] = len2;

        }

        int ans = 0;

        for (int i=1; i<=n; ++i)    {

            ans = max (ans, min (dp[i], dp2[i]) * 2 - 1);

        }

        printf ("%d\n", ans);

    }

    return 0;

}