#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define fr(i,a,b,c) for(int i = a;i<b;i+=c)
#define fre(i,a,b,c) for(int i = a;i>=b;i-=c)
#define fs first
#define sc second
#define all(a) a.begin(),a.end()
#define IINF 2000000005
#define LINF 1000000000000000005
#define MOD 1000000007
#define str string
#define endl '\n'
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using tiii = tuple<int,int,int>;
struct FT{
int n;
vector<int> bit;
void add(int v,int id){
for(;id <= n;id += id & -id)bit[id] += v;
}
int query(int id){
int v = 0;
for(;id > 0;id -= id & -id)v += bit[id];
return v;
}
FT(int n){
bit.resize(n+1);
this->n = n;
}
int qu(int l,int r){
return query(r) - query(l-1);
}
void clear(){
fr(i,1,n+1,1)bit[i] = 0;
}
};
int main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
int n;cin >> n;
vector<int> a(n);
fr(i,0,n,1)cin >> a[i];
vector<vector<int>> pf(n+1,vector<int>(n+1));
FT tree(n);
fr(i,0,n,1){
fr(j,a[i],n+1,1){
pf[j][a[i]] += tree.qu(j + 1,n);
}
tree.add(1,a[i]);
}
tree.clear();
fre(i,n-1,0,1){
fr(j,a[i],n+1,1){
pf[j][a[i]] += tree.qu(a[i],j);
}
tree.add(1,a[i]);
}
fr(i,1,n+1,1){
fre(j,i-1,1,1)pf[i][j] += pf[i][j+1];
}
vector<int> dp(n+1,IINF);
dp[0] = 0;
fr(i,1,n+1,1){
fr(j,1,i+1,1){
dp[i] = min(dp[i],dp[j-1] + pf[i][j]);
}
}
cout << dp[n] << endl;
}
