using System;
public class Program
{
public static void Main()
int[] arr={1,99,1,1,3,2,8,4,1,2,9,5,7,2,6,0,5,3,7,4,7};
Array.Sort(arr);
for(int i=0;i<arr.Length;i++)
if(Array.IndexOf(arr,arr[i])!=Array.LastIndexOf(arr,arr[i]))
Console.WriteLine(arr[i]+" ");
i=Array.LastIndexOf(arr,arr[i])+1;
}