// File groupphoto.cpp created on 30.09.2025 at 19:37:11
#include <bits/stdc++.h>
using i64 = long long;
#ifdef DEBUG
#include "/home/ahmetalp/Desktop/Workplace/debug.h"
#else
#define debug(...) void(23)
#endif
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int N;
std::cin >> N;
std::vector<int> A(N);
for (int i = 0; i < N; ++i) {
std::cin >> A[i];
--A[i];
}
std::vector<int> p(N);
for (int i = 0; i < N; ++i) {
p[A[i]] = i;
}
std::vector<int> s(N);
std::vector<std::vector<int>> g(N, std::vector<int>(N));
std::vector<std::vector<int>> h(N, std::vector<int>(N));
for (int i = 0; i < N; ++i) {
for (int j = A[i]; j < N; ++j) {
s[j]++;
}
for (int j = A[i]; j < N; ++j) {
g[A[i]][j] = s[N - 1] - s[j];
h[A[i]][j] = (j - A[i]) - (s[j] - s[A[i]]);
}
}
std::vector<int> f(N + 1, N * N);
f[0] = 0;
for (int i = 0; i < N; ++i) {
int cost = 0;
for (int j = i; j >= 0; --j) {
cost += g[j][i] + h[j][i];
f[i + 1] = std::min(f[i + 1], f[j] + cost);
}
}
debug(f);
std::cout << f[N] << '\n';
return 0;
}
