#include <bits/stdc++.h>
using namespace std;
int N;
int arr[5005];
int dp[5005];
int cst[5005][5005];
int bit[5005];
int pos[5005];
void upd(int p){
p++;
while(p <= N){
bit[p]++;
p += p&-p;
}
}
int query(int p){
p++;
int ret = 0;
while(p){
ret += bit[p];
p -= p & -p;
}
return ret;
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
/*
cin >> N;
priority_queue<int, vector<int>, greater<int>> pq;
for(int i = 1; i <= N; i++){
cin >> arr[i];
if(i > 1 && arr[i] + 1 < arr[i-1]){
pq.push(i-1);
}
}
int ans = 0;
while(pq.size()){
int n =pq.top();
pq.pop();
if(arr[n+1] + 1 < arr[n]){
swap(arr[n], arr[n+1]);
if(n != 1 && arr[n] + 1 < arr[n-1]){
pq.push(n-1);
}
if(n != N-1 && arr[n+2] + 1 < arr[n+1]){
pq.push(n+1);
}
ans++;
}
}
for(int i = 1; i <= N; i++){
cout << arr[i] << " ";
}
cout << ans;
*/
/*
cin >> N;
for(int i = 1; i <= N; i++){
cin >> arr[i];
}
int ans = 0;
int pos = 0;
for(int l = 1; l <= N;){
int r = l;
for(int i = N; i; i--){
if(arr[i] == r){
r++;
}
}
l = r;
r--;
for(int i = 1; i <= N; i++){
if(arr[i] == r){
pos++;
for(int j = i-1; j >= pos; j--){
ans++;
swap(arr[j], arr[j+1]);
for(int k = 1; k <= N; k++){
cout << arr[k] << " ";
}
cout << "\n";
cout << r << "\n";
}
r--;
}
}
}
cout << ans;
*/
cin >> N;
for(int i = 1; i <= N; i++){
cin >> arr[i];
pos[arr[i]] = i;
dp[i] = INT_MAX/2;
}
for(int l = 1; l <= N; l++){
fill(bit, bit+1+N, 0);
int tot = 0;
int idx = 0;
for(int i = 1; i <= N; i++){
if(arr[i] >= l){
pos[arr[i]] = idx++;
}
}
for(int r = l; r <= N; r++){
tot += query(pos[r]);
tot += pos[r];
upd(pos[r]);
dp[r] = min(dp[r], dp[l-1] + tot - (r - l) * (r - l + 1)/2);
}
}
cout << dp[N];
}
