using System;

namespace ConsoleApp2
{



    class Program
    {
        public static void deque(int[] stack1, int i, int num, ref int nach2, ref int kon2)
        {

            if (i == 1)//push_back
            {
                stack1[kon2] = num;
                kon2++;
            }
            if (i == 2)//push_front
            {
                stack1[nach2] = num;
                nach2--;
            }
        }

        static void Main(string[] args)
        {

            int n;
            n = int.Parse(Console.ReadLine());
            int[] firsthalf = new int[1000000];
            int[] secondhalf = new int[1000000];
            string[] a;
            int nach1 = 0;
            int kon1 = 0;
            int nach2 = 499999;
            int kon2 = 500000;

            for (int i = 0; i < n; ++i)
            {
                while (kon1 - nach1 < kon2 - nach2 - 1)
                {
                    firsthalf[kon1] = secondhalf[nach2 + 1];
                    secondhalf[nach2 + 1] = 0;
                    kon1++;
                    nach2++;
                }
                a = Console.ReadLine().Split();
                if (a[0] == "+")
                {
                    Program.deque(secondhalf, 1, int.Parse(a[1]), ref nach2, ref kon2);

                }

                if (a[0] == "*")
                {

                    Program.deque(secondhalf, 2, int.Parse(a[1]), ref nach2, ref kon2);

                }
                if (a[0] == "-")
                {
                    Console.WriteLine(firsthalf[nach1]);
                    nach1++;
                }
            }
        }
    }
}