public static int ScoreToStars(int score)
        {
            int nbIAs = LevelLoader.iaList.Count;
            int bestScore = 0;

            if (nbIAs > 0)
            {
                if (nbIAs <= 5)
                    for (int i = 1; i <= nbIAs; i++) bestScore += 100 * i;

                else
                    bestScore = 500 * (nbIAs - 2);

                if (score < 2 * bestScore / 6)
                    return 1;
                else if (score < 4 * bestScore / 6)
                    return 2;
                else if (score < 5 * bestScore / 6)
                    return 3;
                else if (score < 6 * bestScore / 6)
                    return 4;
                else if (score == bestScore)
                    return 5;
                else
                    return 0;
            }
            else
            {
                return 5;
            }
        }