List finalGrades = new();

    foreach(int val in grades){
        if(val < 38){
            finalGrades.Add(val);
        }else{
            int roundedGrade = (int)Math.Ceiling((decimal)val /5) *5;
            //Console.WriteLine($"round = {roundedGrade}");
            //Console.WriteLine($"val = {val}");
            //Console.WriteLine($"condition  = {roundedGrade - val}");
            if((roundedGrade - val) < 3){
                finalGrades.Add(roundedGrade);
            }else{
                finalGrades.Add(val);

            }               
        }
    }

    return finalGrades;