using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace Stack_Sum
{
    class Program
    {
        static void Main(string[] args)
        {

            Stack<int> numbers = new Stack<int>();
            string input = Console.ReadLine();
            string[] number = Regex.Split(input, @"\D+");
            foreach (string value in number)
            {
                if (!string.IsNullOrEmpty(value))
                {
                    int i = int.Parse(value);
                    numbers.Push(i);
                }
            }

            while (true)
            {
                string option = Console.ReadLine();
                switch (option.ToLower())
                {
                case "add":
                        int addToStack = Int32.Parse(Console.ReadLine());
                        for (int i = 0; i < 2; i++)
                        {
                            numbers.Push(addToStack);
                        }
                        continue;
                case "remove":
                        int popItem = Convert.ToInt32(Console.ReadLine());
                        if (popItem < numbers.Count)
                        {
                            for (int i = 0; i < popItem; i++)
                            {
                                numbers.Pop();
                            }
                        }

                            continue;
                case "end":
                        int[] arr = numbers.ToArray();
                        int sum = 0;
                        for(int i = 0; i <arr.Length; i++)
                        {
                            sum += arr[i];
                        }
                        Console.WriteLine(sum);

                        break;
                }
            }
        }
    }
}