import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int[] a = new int[n / 2];
            for (int i = 0; i < n / 2; i++)
                a[i] = in.nextInt();

            Arrays.sort(a);
            int sum1 = 0;
            int sum2 = 0;
            for (int i = 0; i < n / 2; i++) {
                sum1 += Math.abs(a[i] - (2 * i + 1));
                sum2 += Math.abs(a[i] - (2 * i + 2));
            }
            out.println(sum1 < sum2 ? sum1 : sum2);
        }

    }
}

