using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        //Enqueue 5 then remove 5

        Enqeue(1);

        Enqeue(2);

        Enqeue(3);

        Enqeue(4);      

        Enqeue(5);

        DeQueue();

        DeQueue();

        DeQueue();

        DeQueue();

        DeQueue();

​

        //Add 5 then remove 4

        Enqeue(21);

        Enqeue(22);

        Enqeue(23);

        Enqeue(24);

        Enqeue(25);

        //Enqeue(2111111);

        DeQueue();

        DeQueue();

        DeQueue();

        DeQueue();

        //Add 5 & remove 6

        Enqeue(31);

        Enqeue(32);

        Enqeue(33);

        Enqeue(34);

        Enqeue(35);

        DeQueue();

        DeQueue();

        DeQueue();

        DeQueue();

        DeQueue();

        DeQueue();

    }

    public static Dictionary<int, List<object>> dict = new Dictionary<int, List<object>>();

    public static void Enqeue(object obj){

        int maxKey = 0;

        if(dict.Count() > 0){       

            maxKey = dict.Keys.Max();

            var list = dict[maxKey];

            //if current list has 5 items then create new key/list

            if(list.Count() == 5){

                List<object> temp = new List<object>() {obj};

                maxKey++;

                //add latest item to the latest key

                dict.Add(maxKey, temp);

            } else {

                //if the previous list has less than 5 items then add the latest to that list

                list.Add(obj);              

            }

        } else {

            // only for initial base case when dictionary doesn't have any key;

            List<object> temp = new List<object>() {obj};

            maxKey++;

            dict.Add(maxKey, temp);

        }   

    }

    public static void DeQueue(){

        if(dict.Count() > 0){

            var minKey = dict.Keys.Min();

            //the smallest key was the first one that was added 

            var list = dict[minKey];

            if(list.Count() > 0) {

                //first item in the list is the first item that was added & the one to be removed first (FIFO)

                Console.WriteLine(list[0]);

                //remove item from list

                list.RemoveAt(0);

            } 

            else if(dict.ContainsKey(minKey +1))

            {

                //Remove key from dictionary if the list is empty

                dict.Remove(minKey);

                list = dict[minKey + 1];

                if(list.Count() > 0) {

                    Console.WriteLine(list[0]);

                    list.RemoveAt(0);

                }

            }

        }

    }

}