#include "bits/stdc++.h"
using namespace std;
#define int long long
# define ll long long
const int MAX = 262144 + 6;
const int LOG = 25;
const int inf = 1e18;
const int mod = 998244353;
bool sort(vector < int > &a){
for(int i = 0; i < a.size() - 1; i++){
if(a[i] > a[i + 1])
return false;
}
return true;
}
void _(){
int n, mn = inf;
cin >> n;
vector < int > a(n);
for(int i = 0; i < n; i++)
cin >> a[i];
for(int i = 0; i < pow(2, n); i++){
int cnt = 1;
vector < bool > vis(n, 0);
for(int j = 0; j < n; j++){
if(i & (1 << j)){
vis[j] = 1;
cnt++;
}
}
vis[n - 1] = 1;
bool f = 1;
vector < int > cur;
for(int j = 0; j < n; j++){
if(!vis[j]) cur.push_back(a[j]);
else {
cur.push_back(a[j]);
if(!sort(cur)){f = 0;break;}
cur.clear();
}
}
if(!f) continue;
bool ii = 1;
vector < int > res;
vector < int > ans;
for(int fr = 0; fr < n; fr++){
if(!vis[fr]) res.push_back(a[fr]);
else {
vector < int > all;
res.push_back(a[fr]);
if(!(int)ans.size()){
for(auto ff : res)
ans.push_back(ff);
res.clear();
continue;
}
int p1, p2;
bool check = 0;
if(res[res.size() - 1] <= ans[0]){
for(auto ff : res) all.push_back(ff);
for(auto ff : ans) all.push_back(ff);
ans = all;
res.clear();
continue;
}
if(res[0] >= ans[ans.size() - 1]){
for(auto ff : ans) all.push_back(ff);
for(auto ff : res) all.push_back(ff);
ans = all;
res.clear();
continue;
}
for(int ff = 0; ff < ans.size() - 1; ff++){
if(ans[ff] <= res[0] && ans[ff + 1] >= res[res.size() - 1]){
p1 = ff, p2 = ff + 1, check = 1;
break;
}
}
if(!check){
ii = 0;
break;
}
else {
for(int ff = 0; ff <= p1; ff++) all.push_back(ans[ff]);
for(auto ff : res) all.push_back(ff);
for(int ff = p2; ff < ans.size(); ff++) all.push_back(ans[ff]);
ans = all;
}
res.clear();
}
}
if(ii) mn = min(mn, cnt);
}
cout << mn << endl;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while(t--) _();
}
