public static List<T> DesordenarLista<T>(List<T> input)
{
    List<T> arr = input;
    List<T> arrDes = new List<T>();

    Random randNum = new Random();
    while (arr.Count > 0)
    {
        int val = randNum.Next(0, arr.Count - 1);
        arrDes.Add(arr[val]);
        arr.RemoveAt(val);
    }

    return arrDes;
}