using System;

public class Program

{

    static int[] GetSingleDimentionalArray(int[,] arr)

    {

        return new int[0];

    }

    public static void Main()

    {

        int[,] arr = {

            {1,2,3,4},

            {4,6,7,8}

        };

        var array = GetSingleDimentionalArray(arr);

    }

}