import java.util.*

fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val c = sc.next()
    println(problem151a(c))
}

fun problem151a(c: String): Char {
    val charArray = charArrayOf('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z')
    return charArray[charArray.indexOf(c.toCharArray()[0]) + 1]
}