using System;

public class Program

{

    public static void Main()

    {

        int [] arr={3,8,7,2,9,4,5,6,1,0};

        int n=arr.Length;

        for(int i=0;i<=n-2;i++)

        {

            for(int j=i+1;j<=n-1;j++)

            {

                if(arr[i]+arr[j]==9)

                {

                    Console.WriteLine(arr[i]+ " , " +arr[j]);

                }

            }

        }

    }

}