/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.08.22 18:13:44
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int main() {
    int n;cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    vector<int> lu(n),ld(n),ru(n),rd(n);
    constexpr int INF = 1e9 + 6;
    vector<int> v(n+1,INF);
    for (int i = 0; i < n; i++) {
        int idx = lower_bound(v.begin(), v.end(), a[i]) - v.begin();
        v[idx] = a[i];
        lu[i] = idx;
    }
    v = vector<int>(n+1,INF);
    for (int i = 0; i < n; i++) {
        int idx = lower_bound(v.begin(), v.end(), -a[i]) - v.begin();
        v[idx] = -a[i];
        ld[i] = idx;
    }
    v = vector<int>(n+1,INF);
    for (int i = n-1; i >= 0; i--) {
        int idx = lower_bound(v.begin(), v.end(), a[i]) - v.begin();
        v[idx] = a[i];
        ru[i] = idx;
    }
    v = vector<int>(n+1,INF);
    for (int i = n-1; i >= 0; i--) {
        int idx = lower_bound(v.begin(), v.end(), -a[i]) - v.begin();
        v[idx] = -a[i];
        rd[i] = idx;
    }
    int ans = 0;
    for (int i = 0; i < n; i++) {
        ans = max({ans,min(lu[i],ru[i]),min(ld[i],rd[i])});
    }
    
    
    
    
    cout << ans << endl;
    return 0;
}