#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2")
#define int long long
#define pii pair<int,int>
#define vi vector<int>
#define ff first
#define ss second
#define sp << " " <<
#define all(x) x.begin(),x.end()
#define big(x) ((int)(x.size()))
using namespace std;
const int MOD = 1e9+7, LIM = 1e6+1, inf = 2e18;
const int N = 2e5+1;
void solve() {
int n;
cin >> n;
vi a(n+1),pos(n+1);
for (int i=1;i<=n;i++) cin >> a[i];
for (int i=1;i<=n;i++) pos[a[i]] = i;
vi dp(n+1,inf);
dp[0] = 0;
for (int i=0;i<n;i++) {
//ilk i yere i sayıyı yerleştirdim
for (int j = i+1;j<=n;j++) {
//[i+1..j] gelcek şimdi
int cost = 0;
for (int k = j;k>=i+1;k--) {
//k -> i+(j-k+1)
int togo = i+(j-k+1);
//get(pos[k])-togo
for (int jj = 1;jj<=pos[k];jj++) {
if (a[jj] <= i || (a[jj] <= j && a[jj] >= k)) continue;
cost++;
}
}
dp[j] = min(dp[j],dp[i]+cost);
}
}
cout << dp[n] << '\n';
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef Dodi
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
#endif
int t = 1;
//cin >> t;
while (t --> 0) solve();
}
