import java.util.Scanner

object Main extends App {
  val sc = new Scanner(System.in)
  val s  = sc.next

  val alphabet = "abcdefghijklmnopqrstuvwxyz"
  val nextAlphabet = "bcdefghijklmnopqrstuvwxyza"

  val res = nextAlphabet.charAt(alphabet.indexOf(s))

  println(res)


}