#define NDEBUG
#ifdef NDEBUG
#define dbg(TXTMSG) if constexpr (false) cerr << "lol"
#define dbgv(VARN) ((void)0)
#define dbgfor(COND) if constexpr (false) for (COND)
#else
#define _GLIBCXX_DEBUG 1
#define _GLIBCXX_DEBUG_PEDANTIC 1
#pragma GCC optimize("trapv")
#define dbg(TXTMSG) cerr << "\n" << TXTMSG
#define dbgv(VARN) cerr << "\n" << #VARN << " = "<< VARN << ", line: " << __LINE__ << "\n"
#define dbgfor(COND) for (COND)
#endif
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll,ll>;
#define e0 first
#define e1 second
constexpr ll INFTY = 1e11;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T>
using oset = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
int main() {
cin.tie(nullptr);
ios_base::sync_with_stdio(false);
ll N;
cin >> N;
vector<ll> H(N);
for (int i = 0; i < N; ++i)
{
cin >> H[i];
H[i]--;
}
// dp[num sorted][desc chain till]
vector<vector<ll>> dp(N,vector<ll>(N,-INFTY));
vector<ll> currelems = H;
vector<ll> pos(N,-1);
for (ll i = 0; i < N; ++i)
{
pos[H[i]]=i;
}
for (ll ns = 0; ns < N; ++ns)
{
ll currcost = INFTY;
for (ll still = 0; still < ns; ++still)
{
currcost = min(currcost,dp[still][ns-1]);
}
if (ns==0)
{
currcost = 0;
}
oset<ll> postaken;
for (ll i = ns; i < N; ++i)
{
currcost+=(pos[i])-ll(postaken.size()-postaken.order_of_key(pos[i]));
postaken.insert(pos[i]);
dbgv(currcost);
dp[ns][i]=currcost;
}
currelems.erase(currelems.begin()+pos[ns]);
pos.assign(N,-1);
for (ll i = 0; i < (ll)currelems.size(); ++i)
{
pos[currelems[i]] = i;
}
}
ll outp = INFTY;
for (ll still = 0; still < N; ++still)
{
outp = min(outp,dp[still][N-1]);
}
dbgfor (int i = 0; i < N; ++i)
{
dbgfor (int j = 0; j < N; ++j)
{
dbg(i << ":" << j << "=" << dp[i][j]);
}
}
cout << outp;
}
