Student.cs

class Student : IComparable<Student>
{
    public string Name { get; set; }
    public int Number { get; set; }
    public int SerialNo { get; set; }
    public int Grade { get; set; }

    public int CompareTo(Student other)
    {
        if (other.SerialNo < SerialNo)
            return 1;
        else if (other.SerialNo == SerialNo)
            return 0;
        else
            return -1;
    }
}