C# convert digites into word

using System;
namespace manoj
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("enter ur num");
string nn = (Console.ReadLine());
int l = nn.Length;
int n = Convert.ToInt32(nn);
int[] aa = new int[l+1];
for (int j = 0; j < l; j++) { aa[j] = n % 10; n = n / 10; } Console.WriteLine(" Entered digits are "); for (int k = l-1; k >= 0; k--)
{
int b = aa[k];
switch (b)
{
case 0:
Console.Write("zero ");
break;
case 1 :
Console.Write("one ");
break;
case 2 :
Console.Write("two ");
break;
case 3 :
Console.Write("three ");
break;
case 4:
Console.Write("four ");
break;
case 5:
Console.Write("five ");
break;
case 6:
Console.Write("six ");
break;
case 7:
Console.Write("seven ");
break;
case 8:
Console.Write("eight ");
break;
case 9:
Console.Write("nine ");
break;
}
}
Console.ReadLine();
} } }


Output:

Enter ur num
7295
Entered digits are
Seven two nine five