fun main(args: Array<String>) {
    val inText = readLine()!!
    val arr = inText.map { it - 'A' }.toMutableList()
    val span = 'Z' - 'A' + 1
    for(i in arr.indices) {
        var newChar = arr[i] - (i+1)
        while (newChar < 0) {
            newChar = newChar + span
        }
        arr[i] = ('A' + newChar).toInt()
    }
    println(arr.map { it.toChar() }.joinToString(""))
}