using System;

class Program

{

 static void Main(string[] args)

 {

 int a;

 Console.Write("Nhap vao a:=");

 a = int.Parse(Console.ReadLine());

 switch (a)

 {

 case 1:

 Console.Write("Day la chu nhat");break;

 case 2:

 Console.Write("Day la thu hai"); break;

 case 3:

 Console.Write("Day la thu ba"); break;

 case 4:

 Console.Write("Day la thu tu"); break;

 case 5:

 Console.Write("Day la thu nam");break;

 case 6:

 Console.Write("Day la thu sau");break;

 case 7:

 Console.Write("Day la thu bay");break;

 default:

 Console.Write("Ko la ngay trong tuan");break;

 }

 Console.ReadKey();

 }

}

​