#include<bits/stdc++.h>
#define int long long
using namespace std;
const int INF=10000000000;
signed main(){
  int N;
  cin>>N;
  vector<int> A(N);
  for(int &i:A)cin>>i;
  vector<int> B(N+2),C(N+2),D(N+1,INF),E(N+1,INF),F(N+1,INF),G(N+1,INF),H(N+2),I(N+2);
  D[0]=-INF,E[0]=-INF,F[0]=-INF,G[0]=-INF;
  for(int i=0;i<N;i++){
    B[i+1]=B[i];
    int it=lower_bound(D.begin(),D.end(),A[i])-D.begin();
    if(D[it]==INF)B[i+1]++;
    D[it]=A[i];
  }
  for(int i=N;i>0;i--){
    C[i]=C[i+1];
    int it=lower_bound(E.begin(),E.end(),A[i-1])-E.begin();
    if(E[it]==INF)C[i]++;
    E[it]=A[i-1];
  }
  for(int i=0;i<N;i++){
    H[i+1]=H[i];
    int it=lower_bound(F.begin(),F.end(),-A[i])-F.begin();
    if(F[it]==INF)H[i+1]++;
    F[it]=-A[i];
  }
  for(int i=N;i>0;i--){
    I[i]=I[i+1];
    int it=lower_bound(G.begin(),G.end(),-A[i-1])-G.begin();
    if(G[it]==INF)I[i]++;
    G[it]=-A[i-1];
  }
  int ans=0;
  for(int i=1;i<=N;i++)ans=max(ans,min(B[i],C[i]));
  for(int i=1;i<=N;i++)ans=max(ans,min(H[i],I[i]));
  cout<<ans-1<<endl;
}