///Borodi
#include <bits/stdc++.h>
using namespace std;

ifstream fin("barman.in");
ofstream fout("barman.out");

int n;
int init[601], dp[601], ok[601];

int main() {
    fin >> n;

    for(int i = 1; i <= n; ++i){
        fin >> init[i];
        dp[i] = init[i];
    }

    int ans = (1 << 28);

    sort(init + 1, init + 1 + n);

    for(int i = 1; i <= n; ++i){

        int sum = 0;

        for(int  j = 1; j <= n; ++j)
            ok[j] = (init[j] == dp[j]);

        for(int  j = 1; j <= n; ++j)
            if(dp[j] != init[j])
                for(int k = 1; k <= n; ++k)
                    if(ok[k] == 0 && init[k] == dp[j]) {
                        sum += 20 + abs(k - j);
                        ok[k] = 1;
                        break;
                    }

        ans = min(ans, sum);

        int aux = init[n];

        for(int j = n - 1; j >= 1; --j)
            init[j + 1] = init[j];

        init[1] = aux;
    }

    fout << ans;

    return 0;
}