using System;

public class Program

{

    public static void Main()

    {

             int[] arr = new int[10];

        int[] arr2 = new int[10];

Random rng = new Random();

for (int z = 0; z < 10; z++) 

{

int n = rng.Next(1, 21);

     int i, m=0, flag=0;

​

          m=n/2;

          for(i = 2; i <= m; i++)

          {

           if(n % i == 0)

            {

                arr2[i] = n;

             Console.WriteLine(n + " is not Prime.");

             flag=1;

             break;

            }

          }

​

}

                  Console.WriteLine("[{0}]", string.Join(", ", arr));

                  Console.WriteLine("[{0}]", string.Join(", ", arr2));

    }

}