#include <iostream>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for (int i = (a); i <= (b); i++)
#define repa(i,a,b) for (int i = (a); i >= (b); i--)
#define lli long long int
#define debugsl(a) cout << #a << " = " << a << ", "
#define debug(a) cout << #a << " = " << a << endl
#define debugarr(x,a,b) cout << #x << " = ["; rep(iii, a, b) cout << x[iii] << ", "; cout << "]\n"
#define MAX 5000
#define INF (1 << 30)
lli n;
lli arr[MAX+2],dp[MAX+2];
lli costo(lli ini, lli fin){
vector<lli> nuevo;
lli cnt, res, pos, t;
res = 0;
rep(i, 1, n){
if (arr[i] >= ini && arr[i] <= fin){
nuevo.push_back(arr[i]);
--cnt;
if (!cnt) break;
}
else if (arr[i] > fin) nuevo.push_back(arr[i]);
}
t = 0;
repa(i, fin, ini){
rep(j, t, nuevo.size() - 1) if (nuevo[j] == i){
pos = j;
break;
}
repa(j, pos, t + 1){
swap(nuevo[j], nuevo[j - 1]);
++res;
}
++t;
}
return res;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >>n;
rep(i,1,n) {
cin >> arr[i];
}
dp[0] = 0;
rep(i,1,n) {
dp[i] = INF;
rep(j,0,i-1) {
dp[i] = min(dp[i], dp[j] + costo(j + 1, i));
}
}
cout << dp[n];
return 0;
}
