#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using vin=vector<int>;
using vll=vector<long long>;
using vvin=vector<vector<int>>;
using vvll=vector<vector<long long>>;
using vstr=vector<string>;
using vvstr=vector<vector<string>>;
using vch=vector<char>;
using vvch=vector<vector<char>>;
using vbo=vector<bool>;
using vvbo=vector<vector<bool>>;
using vpii=vector<pair<int,int>>;
using pqsin=priority_queue<int,vector<int>,greater<int>>;
#define mp make_pair
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep2(i,s,n) for(int i=(s);i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define decp(n) cout<<fixed<<setprecision((int)n)
const ll inf=1e9+7;
const ll INF=1e18;
const ll mod=998244353;

int n;

vin lis(vin& c){
    vin dp(n,inf),num(n);
    int res=0;
    rep(i,n){
        auto itr=lower_bound(all(dp),c[i]);
        if(*itr==inf)res++;
        num[i]=res;
        *itr=c[i];
    }
    return num;
}

int main(){
    cin>>n;
    vin a(n),b(n);
    rep(i,n){
        cin>>a[i];
        b[n-1-i]=a[i];
    }
    vin llis=lis(a),rlis=lis(b);
    rep(i,n){
        a[i]*=-1;
        b[i]*=-1;
    }
    vin llds=lis(a),rlds=lis(b);
    int x=0;
    rep(i,n){
        x=max(x,min(llis[i],rlis[n-1-i])-1);
        x=max(x,min(llds[i],rlds[n-1-i])-1);
        //cout<<llis[i]<<" "<<rlis[n-1-i]<<" "<<llds[i]<<" "<<rlds[n-1-i]<<endl;
    }
    cout<<x<<endl;
}