#include <stdio.h>
#include <algorithm>
#define NMax 610
using namespace std;

const char IN[]="barman.in",OUT[]="barman.out";

struct interval{
	int x,y;
} vec[NMax],t[NMax],p[NMax];

int N,L,Rez=(1<<30);
bool b[NMax];
int v[NMax],a[NMax],s[NMax],o[NMax];

int dist(int x,int y)
{
	if (x>y) swap(x,y);
	return min(y-x,N-y+x);
}

int search(int x)
{
	int i,step;
	for (step=1;step<=L;step<<=1);
	for (i=0;step;step>>=1)
		if (i+step<=L && a[i+step]<=x)
			i+=step;
	return i;
}

void rotate()
{
	int i,x;
	x=s[1];
	for (i=2;i<=N;++i) s[i-1]=s[i];
	s[N]=x;
}

int solve()
{
	int i,ret=0;
	for (i=1;i<=N;++i) o[i]=0;

	for (i=1;i<=N;++i)
		if (v[i]==s[i])
			o[i]=a[i];

	for (i=1;i<=N;++i)
	{
		if (v[i]==s[i]) continue;
		for (int j=1;j<=N;++j)
			if (v[i]==s[j] && !o[j])
			{
				ret+= 20+abs(i-j);
				o[j]=a[i];
				break;
			}
	}
	return ret;
}

int main()
{
	int i;
	freopen(IN,"r",stdin);
	scanf("%d",&N);
	for (i=1;i<=N;++i) scanf("%d",v+i),a[i]=v[i];
	fclose(stdin);

	sort(a+1,a+N+1);
	L=unique(a+1,a+N+1)-a-1;

	for (i=1;i<=N;++i)
		v[i]=search(v[i]),s[i]=v[i];

	sort(s+1,s+N+1);

	for (int j=1;j<=N;++j)
	{
		if (j!=1) rotate();
		Rez=min(Rez,solve());
	}

	freopen(OUT,"w",stdout);
	printf("%d\n",Rez);
	fclose(stdout);

	return 0;
}