Problem:
Score : 100 points

Problem Statement

In the Kingdom of AtCoder, people use a language called Taknese, which uses lowercase English letters.

In Taknese, the plural form of a noun is spelled based on the following rules:

If a noun's singular form does not end with s, append s to the end of the singular form.

If a noun's singular form ends with s, append es to the end of the singular form.

You are given the singular form S of a Taknese noun. Output its plural form.

Constraints

S is a string of length 1 between 1000, inclusive.

S contains only lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

Print the plural form of the given Taknese word.

Sample Input 1

apple

Sample Output 1

apples

apple ends with e, so its plural form is apples.

Sample Input 2

bus

Sample Output 2

buses

bus ends with s, so its plural form is buses.

Sample Input 3

box

Sample Output 3

boxs

Solution in C# (.NET Core 3.1.201) (judge verdict: Wrong Answer)

using System;
using System.Linq;
using System.Security.Cryptography.X509Certificates;

namespace AtcoderProblem
{
    class Program
    {
        static void Main(string[] args)
        {
            string S = Console.ReadLine();
            int len = S.Length - 1;
            string M = S.Substring(len);
            string answer;
            Console.WriteLine(len); //デバッグ
            if(M == "s")
            {
                answer = S + "es";
            }
            else
            {
                answer = S + "s";
            }
            Console.WriteLine(answer);

        }         
    }
}