#if loc||local
#define _GLIBCXX_DEBUG
#endif

#include<bits/stdc++.h>
using namespace std;

#define rep(i,n) for(ll i=0;i<(n);++i)
using ll = int_fast64_t;
using pll = pair<ll,ll>;
constexpr ll INF = 1LL<<60;
constexpr ll MOD = 1e9+7;
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}return 0;}
#if loc||local
template<class T>void dump(T&& t){cerr<<t<<endl;}
template<class T,class... Ts> void dump(T&& h, Ts&&... t){cerr<<h<<", ";dump(forward<Ts>(t)...);}
#else
void dump(){}
template<class T,class... Ts> void dump(T&& h, Ts&&... t){}
#endif
template<class T> istream &operator>>(istream&is,vector<T>&v){for(auto &elemnt:v)is>>elemnt;return is;}
template<class T,class U> istream &operator>>(istream&is,pair<T,U>&p){is>>p.first>>p.second;return is;}
template<class T> ostream &operator<<(ostream& os,vector<T>const& v){for(auto const& vi:v)os<<vi<<" ";return os;}
template<class T,class U> ostream &operator<<(ostream& os,pair<T,U>const& p){os<<p.first<<","<<p.second;return os;}
template<class T>vector<T> vec(size_t a){return vector<T>(a);}
template<class T, class... Ts>auto vec(size_t a, Ts... ts){return vector<decltype(vec<T>(ts...))>(a, vec<T>(ts...));}

ll LIS(const vector<ll>& v){
  ll n=((ll)v.size());
  constexpr ll INF = (1LL<<60);
  vector<ll> lis(n+1,INF);
  lis[0]=-INF;
  for(ll i=0;i<n;++i){
    auto itr = lower_bound(lis.begin(),lis.end(),v[i]);
    *itr=min(*itr,v[i]);
  }
  ll len=0;
  for(ll i=1;i<=n;++i){
    if(lis[i]!=INF)len=i;
  }
  return len;
}

signed main(){

  ll n;
  cin>>n;
  vector<ll> a(n);
  cin>>a;

  vector<ll> lef(n),rig(n);
  {
    vector<ll> lis(n+1,INF);
    lis[0] = 0;
    ll len = 0;
    for(int i=0;i<n;++i){
      auto itr = lower_bound(begin(lis),end(lis),a[i]);
      ll val = *itr;
      *itr = min<ll>(val,a[i]);
      if(lis[len+1]!=INF){
        len++;
      }
      lef[i] = len;
    }
    dump(lef);
  }
  {
    vector<ll> lis(n+1,INF);
    lis[0] = 0;
    reverse(begin(a),end(a));
    ll len = 0;
    for(int i=0;i<n;++i){
      auto itr = lower_bound(begin(lis),end(lis),a[i]);
      ll val = *itr;
      *itr = min<ll>(val,a[i]);
      if(lis[len+1]!=INF){
        len++;
      }
      rig[i] = len;
    }
    reverse(begin(rig),end(rig));
    reverse(begin(a),end(a));
    dump(rig);
  }
  
  ll ans = 0;
  for(int i=1;i+1<n;++i){
    ll ushi = min<ll>(rig[i-1],lef[n-1]-lef[i]);
    ll tapu = min<ll>(lef[i-1],rig[i+1]);
    ll nichia = max<ll>(ushi,tapu);
    chmax(ans,nichia);
  }
  cout<<(ans)<<endl;

}