Calculateur de notes

using System;

public class Program {
    public static double CalculateAverageGrade(int[] grades) {
        // Écrivez votre code ici
    }

    public static void Main(string[] args) {
        string text = Console.ReadLine();
        string[] stringArr = text.Split(",");
        int[] studentGrades = new int[stringArr.Length];
        for (int i = 0; i < stringArr.Length; i++) {
           studentGrades[i] = int.Parse(stringArr[i]);
        }
        double averageGrade = CalculateAverageGrade(studentGrades);
        Console.WriteLine($"Average grade: {averageGrade}");
    }
}