using System;

public class Program

{

    public static void Main()

    {

        int tp = 0;

        while (true)

        {

            bool drm = false;

            int gs1 = Convert.ToInt32(Console.ReadLine());

            tp += gs1;

            for (int i = 2; i < gs1; i++)

                if (gs1 % i == 0) { drm = true; break; }

            if (drm == false) break;

        }

        Console.WriteLine(tp);

    }

}