#include <bits/stdc++.h>
using namespace std;
template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl
using ll = long long;
bool test(int mask, vector<int> a) {
int n = a.size();
vector<int> w = {-1};
for (int i=0; i<n-1; i++) {
if (mask>>i&1) {
w.push_back(i);
}
}
w.push_back(n-1);
vector<vector<int>> v;
for (int i=1; i<(int)w.size(); i++) {
vector<int> tmp;
for (int j=w[i-1]+1; j<=w[i]; j++) {
tmp.push_back(a[j]);
}
v.push_back(tmp);
}
// for (auto p: v) {
// for (int x: p) cout<<x<<" ";
// cout<<" | ";
// }
// cout<<endl;
vector<int> res;
for (auto p: v) {
vector<int> nxt;
bool done = false;
for (int i=0; i<(int)res.size(); i++) {
if (done || res[i] <= p[0]) {
nxt.push_back(res[i]);
} else {
nxt.insert(nxt.end(), p.begin(), p.end());
nxt.push_back(res[i]);
done = true;
}
}
if (!done) {
nxt.insert(nxt.end(), p.begin(), p.end());
}
res = nxt;
// watch(res.size());
// for (int x: res) cout<<x<<" ";
// cout<<endl;
}
// for (int x: res) cout<<x<<" ";
// cout<<endl;
assert((int)res.size() == n);
bool ok = true;
for (int i=1; i<n; i++) {
ok &= (res[i]>=res[i-1]);
}
return ok;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
int n;
cin>>n;
vector<int> a(n);
for (int i=0; i<n; i++) {
cin>>a[i];
}
int ans = n;
for (int mask=0; mask<(1<<(n-1)); mask++) {
if (test(mask, a)) {
ans = min(ans, 1+__builtin_popcount(mask));
}
}
cout<<ans<<endl;
return 0;
}
