using System;

using System.IO;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var number = "12344";

        var splitNumber = number.ToCharArray().ToList();

        var combineNumberString = String.Empty;     

        IEnumerable<string> recordArrangement = FinalCombination(number, combineNumberString,splitNumber);

        recordArrangement.Distinct().ToArray().Count();

​

        Console.WriteLine(recordArrangement.Distinct().ToArray().Count());

    }

    public static IEnumerable<string> FinalCombination(string number,string combineNumberString, List<char> splitNumber){

        while(number != combineNumberString){   

            var record = Arrangement(splitNumber);  

            var firstChar = splitNumber.First();

            splitNumber.RemoveAt(0);

            splitNumber.Add(firstChar);

            combineNumberString = String.Join(String.Empty, splitNumber.ToArray());

            foreach(var rec in record)

                yield return rec;

        };

    }

    public static IEnumerable<string> Arrangement(List<char> number){   

        var i = 0;

        foreach(var num in number){

            var merge = num.ToString();

            var number2 = new List<char>(number);

            number2.RemoveAt(i);

            i++;

            foreach(var num1 in number2){

                merge += num1;

            }

            yield return merge;

        }       

    }

}