Sergey Mozhaykin

Rectangle current = ball.ElementRectangle;
current.X += (int)(3.5f);
current.Y += (int)(3.5f);
ball.ElementRectangle = current;

namespace TestApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Item.ItemManager manager = new Item.ItemManager();
            //Item i = new Item("name", 0); //'TestApp.Item' does not contain a constructor that takes 2 arguments
            Item i1 = manager.CreateItem("item", 1);
            Console.WriteLine(i1); //Output: "Item id=1, name=item"
            //i1.Id = 2; //The property or indexer 'TestApp.Item.Id' cannot be used in this context because the set accessor is inaccessible
            //i1.Name = "item1"; //The property or indexer 'TestApp.Item.Name' cannot be used in this context because the set accessor is inaccessible
            manager.ChangeId(i1, 2);
            manager.ChangeName(i1, "item1");
            Console.WriteLine(i1); //Output: "Item id=2, name=item1"
            Console.ReadLine();
        }
    }


    
    public class Item
    {
        public string Name { get; private set; }
        public int Id { get; private set; }
        
        private Item(string _name, int _id)
        {
            Name = _name;
            Id = _id;
        }

        public override string ToString()
        {
            return string.Format("Item id={0}, name={1}", Id, Name);
        }
        
        public class ItemManager
        {
            public Item CreateItem(string name, int id)
            {
                return new Item(name, id);
            }

            public void ChangeName(Item item, string newName)
            {
                item.Name = newName;
            }

            public void ChangeId(Item item, int newId)
            {
                item.Id = newId;
            }
        }
    }
}

<configuration>
  <system.net>
    <connectionManagement>
      <add address = "*" maxconnection = "100" />
    </connectionManagement>
  </system.net>
</configuration>

double si = 1.0 / 6; // initial value for i = 1
double s = 0;
int i = 2;
double eps = double.Parse(Console.ReadLine());
while (Math.Abs(si) >= eps)
{
    s += si;
    si = -1 * si * (i - 1) / (i + 2);
    i++;
}
Console.WriteLine(s);
Console.ReadLine();