#include <bits/stdc++.h>
using namespace std;
#define io ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define ALL(x) x.begin(),x.end()
#define SZ(x) x.size()
#define PB push_back
#define MP make_pair
#define F first
#define S second
typedef long long LL;
typedef vector<int> VI;
typedef pair<int,int> PI;

int n,a[5000],ans,Z[5000][2];

int solve() {
   Z[0][0] = 1;
   Z[0][1] = 1;
   int cnt = 0;
   for(int i = 1; i < n; i++) {
      for(int j = i-1; j >= 0; j--){
         if(a[j] <= a[i]) Z[i][0] = max(Z[j][1]+1,Z[i][0]);
         if(a[j] >= a[i]) Z[i][1] = max(Z[j][0]+1,Z[i][1]);
      }
      cnt = max(cnt,max(Z[i][0],Z[i][1]));
   }
   return cnt;
}

int main() {
   io
   cin >> n;
   for(int i = 0; i < n; i++)
      cin >> a[i];
   cout << solve();
}