#include<fstream>
#include<algorithm>
using namespace std;ifstream f("barman.in");ofstream g("barman.out");int a[610],v[610],w[610];int main(){int n,j,i,x,c;f>>n;for(i=1; i<=n; ++i){f>>a[i];v[i]=a[i];}sort(v+1,v+n+1);int k=n,m=2000000000;while(k--){x=v[1];for(int i=1; i<n; ++i) v[i]=v[i+1];v[n]=x;for(int i=1; i<=n; ++i){w[i]=(a[i]==v[i]);}c=0;for(int i=1; i<=n; ++i)if(a[i]!=v[i]){for(j=1; w[j]||a[i]!=v[j]; ++j);w[j]=1;c+=20+max(i,j)-min(i,j);}m=min(m,c);}g<<m;return 0;}