import java.util.*

fun main() {
    val pw = java.io.PrintWriter(System.out)
    Problem.solve(Scanner(System.`in`), pw)
    pw.flush()
}

object Problem {
    fun solve(sc: Scanner, pw: java.io.PrintWriter) {
        val S = sc.next()
        pw.println(S + if (S.endsWith("s")) "es" else "s")
    }
}
