using System;
using System.Collections.Generic;
using System.Linq;
using System.Globalization;

public class Test
{
 
	public static void Main()
	{
            int[] seq = new[] { 2, 1, 1, 2, 3, 3, 2, 2, 2, 1 };
            int[] maxSeq = seq
                .Select((i, index) => new{ 
                    Item = i, index,
                    PrevEqual = index == 0 || seq.ElementAt(index - 1) == i
                })
                .Where(x => x.PrevEqual)
                .GroupBy(x => x.Item)
                .OrderByDescending(g => g.Count())
                .First().Select(x => x.Item).ToArray();

            Console.Write(string.Join(",", maxSeq.Select(i => i.ToString()).ToArray()));
	}
}