#include <bits/stdc++.h>
using namespace std;
const int MAXN = 5005;
const int INF = 0x3f3f3f3f;
struct SegTree {
int seg[4*MAXN];
void build(int node, int l, int r) {
if (l == r) {
seg[node] = 0;
return;
}
int m = (l+r)/2;
build(2*node, l, m);
build(2*node + 1, m + 1, r);
seg[node] = (seg[2*node] + seg[2*node + 1]);
}
int query(int node, int l, int r, int tl, int tr) {
if ((r < tl) || (tr < l)) return 0;
if ((tl <= l) && (r <= tr)) return seg[node];
int m = (l + r)/2;
return (query(2*node, l, m, tl, tr) + query(2*node + 1, m + 1, r, tl, tr));
}
void update(int node, int l, int r, int po, int val) {
if (l == r) {
seg[node] = val;
return;
}
int m = (l + r)/2;
if (po <= m) update(2*node, l, m, po, val);
else update(2*node + 1, m + 1, r, po, val);
seg[node] = (seg[2*node] + seg[2*node + 1]);
}
};
SegTree seg;
int dp[MAXN];
int32_t main() {
int n;
cin >> n;
vector<int> v(n + 1);
for (int i = 1; i <= n; i++) cin >> v[i];
for (int k = 1; k <= n; k++) {
dp[k] = INF;
vector<int> nv, po(k + 1);
for (int i = 1; i <= n; i++) {
if (v[i] <= k) {
nv.push_back(v[i]);
}
}
for (int i = 0; i < k; i++) {
po[nv[i]] = (i + 1);
}
seg.build(1, 1, k);
int calc = 0;
for (int i = k; i >= 1; i--) {
calc += (k - po[i]);
calc -= seg.query(1, 1, k, 1, po[i]);
seg.update(1, 1, k, po[i], 1);
dp[k] = min(dp[k], dp[i - 1] + calc);
}
}
cout << dp[n] << "\n";
}
