using System;

namespace _05_wordInPlural
{
    class Program
    {
        static void Main(string[] args)
        {
            string word = Console.ReadLine().ToLower();
            int wordLenght = word.Length;
            bool endsInY = word.EndsWith('y');
            bool endsInOtoH = word.EndsWith('o') || word.EndsWith("ch") || word.EndsWith('s') || word.EndsWith("sh")
                || word.EndsWith('x') || word.EndsWith('z') || word.EndsWith('h');

            if (endsInY)
            {
                word = word.Remove(wordLenght - 1, 1);
                word = word + "ies";
            }
            else if (endsInOtoH)
            {
                word = word + "es";
            }
            else
            {
                word = word + "s";
            }
            Console.WriteLine(word);
        }
    }
}