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 Go (1.14.1) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
)

func main() {
	sc := NewScanner()

	s := sc.ReadString()

	if s[len(s)-1] == 's' {
		fmt.Println(s + "es")
	} else {
		fmt.Println(s + "s")
	}
}

// from [my library](https://github.com/ikngtty/go-contestlib)
// -   math/simple

func Abs(x int) int {
	if x >= 0 {
		return x
	}
	return -x
}

func Min(values ...int) int {
	if len(values) == 0 {
		panic("no values")
	}

	min := values[0]
	for _, v := range values {
		if v < min {
			min = v
		}
	}
	return min
}

func Max(values ...int) int {
	if len(values) == 0 {
		panic("no values")
	}

	max := values[0]
	for _, v := range values {
		if v > max {
			max = v
		}
	}
	return max
}

func Pow(base, exponent int) int {
	if exponent < 0 {
		panic(fmt.Sprintf("exponent (%d) should not be a minus", exponent))
	}

	answer := 1
	for i := 0; i < exponent; i++ {
		answer *= base
	}
	return answer
}

func Ceil(divident, dividor int) int {
	if dividor == 0 {
		panic("dividor should not be 0")
	}

	quo := divident / dividor
	rem := divident % dividor

	if rem != 0 {
		if (divident > 0 && dividor > 0) ||
			(divident < 0 && dividor < 0) {
			return quo + 1
		}
	}
	return quo
}

// -   sortutil

func ReverseInts(a []int) {
	sort.Sort(sort.Reverse(sort.IntSlice(a)))
}

func ReverseStrings(a []string) {
	sort.Sort(sort.Reverse(sort.StringSlice(a)))
}

// -   io

type Scanner struct {
	bufScanner *bufio.Scanner
}

func NewScanner() *Scanner {
	bufSc := bufio.NewScanner(os.Stdin)
	bufSc.Split(bufio.ScanWords)
	bufSc.Buffer(nil, 100000000)
	return &Scanner{bufSc}
}

func (sc *Scanner) ReadString() string {
	bufSc := sc.bufScanner
	bufSc.Scan()
	return bufSc.Text()
}

func (sc *Scanner) ReadInt() int {
	bufSc := sc.bufScanner
	bufSc.Scan()
	text := bufSc.Text()

	num, err := strconv.Atoi(text)
	if err != nil {
		panic(err)
	}
	return num
}

func (sc *Scanner) ReadFloat() float64 {
	bufSc := sc.bufScanner
	bufSc.Scan()
	text := bufSc.Text()

	num, err := strconv.ParseFloat(text, 64)
	if err != nil {
		panic(err)
	}
	return num
}