public static string gridChallenge(List<string> grid)
    {
        for (int i = 0; i < grid.Count(); i++)
        {
            char[] characters = grid[i].ToArray();
            Array.Sort(characters);
            grid[i] = new string(characters);
        }

        bool alphaOrder = true;
        if (grid.Count > 1)
        {
            for (int i = 0; i < grid.Count() - 1; i++)
            {
                for (int j = 0; j < grid[0].Count(); j++)
                {
                    if (String.Compare(grid[i].Substring(j, 1), grid[i + 1].Substring(j, 1)) > 0)
                    {

                        alphaOrder = false;
                    }
                }
            }
        }

        return alphaOrder ? "YES" : "NO";

    }