using System;

public class Program

{

    public static void Main()

    {

        int[] flights = new int[] {5,11,9,13,8,30,14};

        int stairsPerStride = 3;

        int strides = (flights.Length - 1) * 2;

        for (int i=0, l = flights.Length; i < l; i++)

        {

            strides += flights[i] / stairsPerStride;

            if (flights[i] % stairsPerStride > 0)

                strides++;

        }

        Console.WriteLine(strides);

    }

}