using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var str = "Today is the  ever greatest   day";

        var words = str.Split(' ');

        var result = "";

        var maxRepeatedLetters = 0;

        foreach(var word in words){

            var charCounts = new Dictionary<char, int>();

            var maxCharCount = 0;

            var maxChar = ' ';

            var value = 0;

            var res = 0;

            foreach(var c in word){

                if(!charCounts.TryGetValue(c, out value)){

                    charCounts.Add(c, 1);

                    continue;

                }

                value++;

                if(value > maxCharCount){

                    maxCharCount = value;

                    maxChar = c;

                }

            }

            if(maxCharCount > maxRepeatedLetters){

                maxRepeatedLetters = maxCharCount;

                result = word;

            }

        }

        if(string.IsNullOrEmpty(result)){

            Console.WriteLine("-1");

        }else{

            Console.WriteLine(result);

        }

    }

}