C# inherit

Case：class A has a construct. class B is inherit from class A and B also has a construct. What's the order of the construct execute?

Result: construct A -> construct B.

Sample:

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace TestInheritConstruct
 {
     public class Program
     {
         public static void Main(string[] args)
         {
             B b = new B();
             Console.ReadLine();
         }
     }

     public class A
     {
         public A()
         {
             Console.WriteLine("Construct A.");
         }
     }

     public class B : A
     {
         public B()
         {
             Console.WriteLine("Construct B.");
         }
     }
 }