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

namespace MyCompiler 
{
    class Program 
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Hello world!");
            method(new string[]{"Empty","ace", "spades", "hearts", "clubs" });
            method(new string[]{ "one", "two", "three"  });
        }
        public static void method(string[] arr)
        {
            arr = arr.Where(x => x == string.Concat(x.OrderBy(d => d))).ToArray();
            List<string> lis = arr.ToList();
            lis.Sort((x,y) =>
            {
                return x.Length.CompareTo(y.Length);
            });
            lis.Reverse();
            Console.WriteLine(lis.Count() == 0 ?"":lis[0]);
        }
    }
}