using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        List<List<string>> Permutations = new List<List<string>>();

​

        List<string> ls1 = new List<string>() {"+", "-", "x", "/"};

        Permutations.Add(ls1);

​

        List<string> ls2 = new List<string>() {"+", "-", "/", "x"};

        Permutations.Add(ls2);

        Console.WriteLine(Permutations.Count);

        foreach (var ls in Permutations) {

            foreach (string str in ls) {

                Console.WriteLine(str);

            } 

        }

    }

}