#include <bits/stdc++.h>
using namespace std;
template <class T>
struct fenwick {
vector<T> tree;
int n;
fenwick(int n) : n(n) {
tree.resize(n + 1);
}
void update(int a, T x) {
for ( ; a <= n; a += (a & -a)) {
tree[a] += x;
}
}
T query(int a) {
T res = 0;
for ( ; a > 0; a -= (a & -a)) {
res += tree[a];
}
return res;
}
int lower_bound(T k) {
int res = 0;
T sum = 0;
for (int i = __lg(n); i >= 0; --i) {
if (res + (1 << i) <= n && sum + tree[res + (1 << i)] < k) {
res += 1 << i;
sum += tree[res];
}
}
return res + 1;
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
vector<int> perm(n), where(n);
for (int i = 0; i < n; ++i) {
cin >> perm[i];
where[--perm[i]] = i;
}
vector<int> ans(n + 1, n * n);
ans[0] = 0;
for (int i = 0; i < n; ++i) {
int segment = 0;
fenwick<int> sum(n);
for (int j = 0; i + j < n; ++j) {
segment += where[i + j] - j + sum.query(where[i + j]);
ans[i + j + 1] = min(ans[i + j + 1], ans[i] + segment);
sum.update(where[i + j] + 1, 1);
}
for (int j = i + 1; j < n; ++j) {
where[j] -= where[j] > where[i];
}
}
cout << ans[n] << "\n";
}
