1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace ConsoleApplication1
 8 {
 9     class Program
10     {
11         class Vector
12         {
13             public int value;
14         }
15         static void Main(string[] args)
16         {
17             Vector x, y;
18             x = new Vector();
19             x.value = 30;
20             y = x;
21             Console.WriteLine(y.value);
22             y.value = 10;
23             Console.WriteLine(x.value);
24             Console.ReadKey();
25         }
26     }
27 }