#include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
typedef long double ld;
#define MP make_pair
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define MT make_tuple
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
#ifdef DEBUG
#define debug(args...) _debug(args)
void _debug(const char* format, ...) {
va_list args;
va_start(args, format);
vprintf(format, args);
va_end(args);
}
#else
#define debug(args...)
#endif
#define INF 1000000005
#define LINF 1000000000000000005
#define MOD 1000000007
#define MAXN 5005
int n;
int h[MAXN];
int mp[MAXN];
int dp[MAXN]; // minimum number of swaps with heights [1 ... i]
int fw1[MAXN], fw2[MAXN];
void incre(int i, int x, int* fw) {
for (; i <= n; i += i & -i) fw[i] += x;
}
int qsm(int i, int* fw) {
int res = 0;
for (; i > 0; i -= i & -i) res += fw[i];
return res;
}
int qsm(int s, int e, int* fw) {
return qsm(e, fw) - qsm(s - 1, fw);
}
int main() {
scanf("%d", &n);
REP (i, 1, n + 1) {
scanf("%d", &h[i]);
mp[h[i]] = i;
}
dp[1] = 0;
REP (i, 2, n + 1) {
dp[i] = INF;
memset(fw1, 0, sizeof fw1);
memset(fw2, 0, sizeof fw2);
REP (j, 1, i + 1) {
incre(mp[j], 1, fw1);
}
int cost = 0;
RREP (j, i, 1) {
cost -= qsm(1, mp[j] - 1, fw2) * 2;
cost += i - j;
cost += qsm(mp[j] + 1, n, fw1);
// consider placing i at position j, so before position j, minimum
// swaps is dp[j - 1] and after position j, the array is
// [i, i - 1, i - 2, ..., j]
mnto(dp[i], dp[j - 1] + cost);
incre(mp[j], -1, fw1);
incre(mp[j], 1, fw2);
}
}
printf("%d\n", dp[n]);
return 0;
}
/*
5
3 5 2 4 1
*/
