// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>
using namespace std;
#define nl '\n'
template<class T> using V = vector<T>;
struct BIT {
int N; V<int> data;
void init(int n) { N = n; data = V<int>(N, 0); }
void add(int p, int x) { for(++p;p<=N;p+=p&-p) data[p-1] += x; }
int sum(int l, int r) { return sum(r+1) - sum(l); }
int sum(int r) { int s = 0; for(;r;r-=r&-r) s += data[r-1]; return s; }
};
const int INF = 1e9 + 10;
int main() {
cin.tie(0)->sync_with_stdio(0);
int N; cin >> N;
V<int> A(N); for(auto& x : A) cin >> x;
V<int> dp(N+1, INF); dp[0] = 0;
for(int x = 0; x <= N; x++) {
BIT B; B.init(N+1);
V<int> amt(N+1);
int seen = 0;
for(int i = 0; i < N; i++) if (A[i] > x) {
int R = N - i - 1;
int lx = R - (N - x - seen - 1);
int l = R - (N - A[i] - B.sum(A[i], N));
// cout << seen << " " << l << " " << lx << endl;
amt[A[i]] = seen - (l - lx);
// cout << A[i] << " " << amt[A[i]] << endl;
B.add(A[i], 1); seen++;
}
int cost = dp[x];
// cout << "X: " << x << " " << cost << endl;
for(int i = x + 1; i <= N; i++) {
cost += amt[i];
// cout << i << " " << cost << endl;
dp[i] = min(dp[i], cost);
}
// cout << endl;
}
cout << dp[N] << nl;
return 0;
}
