using System;

public class Program

{

    public static void Main()

    {

        string s; ulong number, Sum;

        number = 0;

        Sum = 0;

        do

        {

           s = Console.ReadLine();

           number = ulong.Parse(s);

           Sum = Sum + number;

           if (number > 0) continue;

           else break;

        }

        while (true);

           Console.WriteLine("Sum = {0}", Sum);

    }

}