One91

 public static void Main(string[] args)  
     {  
       {  
         int i = 5;  
         while (i >= 1)  
         {  
           int j = 5;  
           while (j >= i)  
           {  
             Console.Write(j);  
             j--;  
           }  
           i--;  
           Console.WriteLine();  
         }  
         Console.Read();  
       }  
     }