#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,b,e) for (int i=(int)(b); i<(int)(e); i++)
#define ALL(x) (x).begin(), (x).end()

const double PI = acos(-1);
const int INF = 1<<30;

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n;
  cin >> n;
  vector<int> a(n);
  REP (i, n) cin >> a[i];

  vector<int> pref(n), suff(n);
  vector<int> dp(n); 

  // mountain
  int r1 = 0;
  fill(dp.begin(), dp.end(), INF);
  REP (i, n) {
    int j = lower_bound(dp.begin(), dp.end(), a[i]) - dp.begin();
    dp[j] = a[i];
    pref[i] = j;
  }
  fill(dp.begin(), dp.end(), INF);
  REP (i, n) {
    int j = lower_bound(dp.begin(), dp.end(), a[n-1-i]) - dp.begin();
    dp[j] = a[n-1-i];
    suff[n-1-i] = j;
  }
  REP (i, n) r1 = max(r1, min(pref[i], suff[i]));

  // valley
  int r2 = 0;
  fill(dp.begin(), dp.end(), INF);
  REP (i, n) {
    int j = lower_bound(dp.begin(), dp.end(), -a[i]) - dp.begin();
    dp[j] = -a[i];
    pref[i] = j;
  }
  fill(dp.begin(), dp.end(), INF);
  REP (i, n) {
    int j = lower_bound(dp.begin(), dp.end(), -a[n-1-i]) - dp.begin();
    dp[j] = -a[n-1-i];
    suff[n-1-i] = j;
  }
  REP (i, n) r2 = max(r2, min(pref[i], suff[i]));
  
  cout << max(r1, r2) << endl;
  
  return 0;
}