import java.io.BufferedReader;
import java.io.IOException;
import java.util.StringTokenizer;

public class GEE1006
{
    public static void main(String args[])
    {
        java.io.BufferedReader bin = new BufferedReader(
                new java.io.InputStreamReader(System.in));
        try
        {
            int i, n, sum;
            int number[];
            String temp = bin.readLine();
            while (temp.indexOf(' ') != -1)
            {
                number = new int[100];
                StringTokenizer s = new StringTokenizer(temp);
                n = s.countTokens();
                i = 0;
                number[i++] = Integer.parseInt(s.nextToken());
                while (s.hasMoreTokens())
                {
                    number[i++] = Integer.parseInt(s.nextToken());
                }
                sum = 0;
                for (i = 0; i < n; ++i)
                {
                    if (i == 0)
                        sum += (number[i] * 6);
                    else
                    {
                        if (number[i] < number[i - 1])
                        {
                            sum += ((number[i - 1] - number[i]) * 4);
                        }
                        else if (number[i] > number[i - 1])
                        {
                            sum += ((number[i] - number[i - 1]) * 6);
                        }
                    }

                    if (i != n - 1)
                        sum += 5;
                }
                System.out.println(sum);

                temp = bin.readLine();
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}