using System;
using System.Collections.Generic;
using System.Linq;
					
public class Program
{
	public static void Main()
	{
		
		var list = new List<int> {0,1,2,3,4,5,6,7,8,9};
		
		var list2 = new List<int> {0,1,2,3,4,5,6,7,8,9};
		
		
		FilterList(list);
		
		list2 = FilterList2(list2);
		
		Console.WriteLine(list.Count());
		Console.WriteLine(list2.Count());

	}
	
	private static void FilterList(List<int> filter)
	{
		filter = filter.Where(x=>x != 0).ToList();
	}
	
	private static List<int> FilterList2(List<int> filter)
	{
		return filter.Where(x=>x != 0).ToList();
	}
	
}