#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define pb push_back
#define eb emplace_back
#define pii pair<int,int>
#define X first
#define Y second
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T i, U ...j) {
cout << i << ' ', abc(j...);
}
template <typename T> void printv(T l, T r) {
for (; l != r; ++l) cout << *l << " \n"[l + 1 == r];
}
#ifdef Doludu
#define test(x...) abc("[" + string(#x) + "]", x)
#define owo freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#else
#define test(x...) void(0)
#define owo ios::sync_with_stdio(false), cin.tie(0)
#endif
const int N = 200000;
int main () {
owo;
int n;
cin >> n;
vector <int> p(n);
for (int i = 0; i < n; ++i)
cin >> p[i], --p[i];
vector <int> dp(n + 1, 1 << 30);
vector <vector <int>> cost(n + 1, vector <int> (n + 1, 0));
vector <vector <int>> inversion(n + 1, vector <int> (n + 1, 0));
for (int i = 0; i < n; ++i) {
for (int j = i + 1; j < n; ++j) {
if (p[i] > p[j])
inversion[p[j]][p[i] + 1]++;
}
}
for (int i = 0; i < n; ++i) {
for (int j = 0; j < n; ++j) {
inversion[i][j + 1] += inversion[i][j];
}
}
vector <int> q(n);
for (int r = 1; r <= n; ++r) {
int t = 0;
for (int i = 0; i < n; ++i) if (p[i] < r)
q[p[i]] = t++;
for (int l = r - 1; ~l; --l) {
cost[l][r] = cost[l + 1][r] + r - q[l] - 1 - inversion[l][r];
}
}
dp[0] = 0;
for (int i = 1; i <= n; ++i) {
for (int j = 0; j < i; ++j) {
// max at postion j
dp[i] = min(dp[i], dp[j] + cost[j][i]);
}
}
cout << dp[n] << endl;
}
