Problem:
Score : 200 points

Problem Statement

For a string S consisting of the uppercase English letters P and D, let the doctoral and postdoctoral quotient of S be the total number of occurrences of D and PD in S as contiguous substrings. For example, if S = PPDDP, it contains two occurrences of D and one occurrence of PD as contiguous substrings, so the doctoral and postdoctoral quotient of S is 3.

We have a string T consisting of P, D, and ?.

Among the strings that can be obtained by replacing each ? in T with P or D, find one with the maximum possible doctoral and postdoctoral quotient.

Constraints

1 \leq |T| \leq 2 \times 10^5

T consists of P, D, and ?.

Input

Input is given from Standard Input in the following format:

T

Output

Print one string with the maximum possible doctoral and postdoctoral quotient among the strings that can be obtained by replacing each ? in T with P or D.
If there are multiple such strings, you may print any of them.

Sample Input 1

PD?D??P

Sample Output 1

PDPDPDP

This string contains three occurrences of D and three occurrences of PD as contiguous substrings, so its doctoral and postdoctoral quotient is 6, which is the maximum doctoral and postdoctoral quotient of a string obtained by replacing each ? in T with P or D.

Sample Input 2

P?P?

Sample Output 2

PDPD

Solution in Kotlin (1.3.71) (judge verdict: Time Limit Exceeded)

/** B */
fun main(args: Array<String>) {

    var t = readLine()!!
    var tempEvalString = t
    while (tempEvalString.contains("?")) {
        val index = tempEvalString.indexOfFirst { it == '?' }
        val nextIndex = index + 1

        // 次の文字があるならまとめて評価
        tempEvalString = if (t.length > nextIndex) {
            when {
                t[nextIndex] == '?' -> {
                    tempEvalString.replaceRange(index, nextIndex + 1, "PD")
                }
                t[nextIndex] == 'D' -> {
                    tempEvalString.replaceRange(index, index + 1, "P")
                }
                else -> {
                    tempEvalString.replaceRange(index, index + 1, "D")
                }
            }
        } else {
            tempEvalString.replaceRange(index, index + 1, "D")
        }
    }

    println(tempEvalString)
}