public class Employee
{
    private string name;
    private int id;

    public Employee(string s, int i)
    {
        name = s;
        id = i;
    }

    public string Name
    {
        get { return name; }
        set { name = value; }
    }

    public int ID
    {
        get { return id; }
        set
 
 { id = value; }
    }
}

public class GenericList<T> where T : Employee
{
    private class Node
    {
        private Node next;
        private T data;

        public Node(T t)
        {
            next = null;
            data = t;
        }

        public Node Next
        {
            get
 
 { return next; }
            set { next = value; }
        }

        public T Data
        {
            get { return data; }
            set { data = value; }
        }
    }

    private Node head;

    public GenericList() //constructor
    {
        head = null;
    }

    public void AddHead(T t)
    {
        Node n = new
 
 Node(t);
        n.Next = head;
        head = n;
    }

    public IEnumerator<T> GetEnumerator()
    {
        Node current = head;

        while (current != null)
        {
            yield return current.Data;
            current = current.Next;
        }
    }

    public T FindFirstOccurrence(string s)
    {
        Node current = head;
        T t = null;

        while (current != null)
        {
            //The constraint enables access to the Name property.
            if (current.Data.Name == s)
            {
                t = current.Data;
                break;
            }
            else
            {
                current = current.Next;
            }
        }
        return t;
    }
}