import java.util.*

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

    var ans = StringBuilder()
    for (c in t) {
      var value = c
      if (c == '?') {
        value = 'D'
      }
      ans.append(value)
    }

    println(ans.toString())

}
