#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
using namespace std;
typedef long long ll;
class fenw{
vector <ll> bit;
ll vel;
public:
fenw(ll a){
vel = a;
bit.resize(a+1);
}
void upd(ll x, ll val){
while (x <= vel){
bit[x] += val;
x += x&-x;
}
}
ll sum(ll x){
ll s = 0;
while (x > 0){
s += bit[x];
x -= x&-x;
}
return s;
}
};
int main()
{
ll n;
cin >> n;
vector <ll> a(n);
for (int i = 0; i < n; i++)
cin >> a[i];
fenw bit1(n);
vector <ll> poz(n+1);
for (int i = 0; i < n; i++)
poz[a[i]] = i + 1;
vector <ll> dp(n+1, 1000000000000000000);
dp[0] = 0;
for (int i = 0; i < n; i++){
fenw inv(n);
ll brin = 0;
ll dodatne_poz = 0;
ll trenutne_poz = 0;
for (int j = i + 1; j <= n; j++){
trenutne_poz += j;
dodatne_poz += poz[j] + bit1.sum(n) - bit1.sum(poz[j]);
//cout << trenutne_poz << " " << dodatne_poz << endl;
brin += inv.sum(n) - inv.sum(poz[j]);
//cout << brin << endl;
inv.upd(poz[j], 1);
ll tren = dp[i] + dodatne_poz - trenutne_poz;
ll manji = min(brin, ((j-i)*(j-i-1))/2 - brin);
tren += manji;
dp[j] = min(dp[j], tren);
}
bit1.upd(poz[i+1], 1);
}
cout << dp[n];
}
