#include <bits/stdc++.h>
using namespace std;
const int INF = (int)1e9 + 123456;
struct Fenwick {
int n;
vector<int> bit;
Fenwick(int n) : n(n), bit(n + 1, 0) {}
void add(int i, int delta) {
for (i++; i <= n; i += i & -i) {
bit[i] += delta;
}
}
int sum(int i) {
int res = 0;
for (; i > 0; i -= i & -i) {
res += bit[i];
}
return res;
}
};
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
vector<int> a(n);
vector<int> ia(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
a[i]--;
ia[a[i]] = i;
}
vector<vector<int>> cost(n, vector<int>(n));
vector<int> offset(n, 0);
for (int l = 0; l < n; l++) {
Fenwick fen(n);
int inv = 0;
int sum_indices = 0;
for (int r = l; r < n; r++) {
inv += fen.sum(ia[r]);
fen.add(ia[r], +1);
sum_indices += ia[r] + offset[ia[r]];
cost[l][r] = inv + sum_indices - (r - l) * (r - l + 1) / 2;
}
for (int i = ia[l] + 1; i < n; i++) {
offset[i]--;
}
}
vector<int> dp(n + 1, INF);
dp[0] = 0;
for (int i = 0; i < n; i++) {
for (int j = i; j >= 0; j--) {
dp[i + 1] = min(dp[i + 1], dp[j] + cost[j][i]);
}
}
cout << dp[n] << '\n';
}
