#include <bits/stdc++.h>
#include <experimental/random>
#include <random>
using namespace std;
using ll = long long;
using ld = long double;
const ll INF = 1e18, MOD = 998244353;
void solve();
signed main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
ll q = 1;
//cin >> q;
while (q--) {
solve();
}
}
struct fenwick {
vector<ll> a;
void change(ll i, ll x) {
for (; i < a.size(); i += i & -i) {
a[i] += x;
}
}
ll get(ll l, ll r) {
ll ans = 0;
for (; l > 0; l -= l & -l) {
ans -= a[l];
}
for (; r > 0; r -= r & -r) {
ans += a[r];
}
return ans;
}
};
void solve() {
ll n;
cin >> n;
vector<ll> a(n);
vector<ll> pos(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
a[i]--;
pos[a[i]] = i;
}
vector<vector<ll>> val(n, vector<ll>(n));
fenwick t1; t1.a.resize(n + 1);
vector<ll> cur(n);
for (int i = 0; i < n; i++) {
cur[i] = t1.get(pos[i] + 1, n);
t1.change(pos[i] + 1, 1);
ll cnt = 0;
fenwick t2; t2.a.resize(n + 1);
for (int j = i; j >= 0; j--) {
cnt -= t2.get(0, pos[j]);
cnt += t1.get(pos[j] + 1, n);
val[j][i] = cnt;
t2.change(pos[j] + 1, 1);
}
}
vector<ll> dp(n, INF);
dp[0] = 0;
for (int i = 1; i < n; i++) {
for (int j = i; j > 0; j--) {
dp[i] = min(dp[i], dp[j - 1] + val[j][i]);
}
dp[i] = min(dp[i], val[0][i]);
}
cout << dp[n - 1];
}
