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: Wrong Answer)

fun main(args:Array<String>) {
    val pd = readLine()!!.split("")
    var ans = ""
    var a = ""
    pd.forEach { i ->
        when (i) {
            "P" -> {
                ans += "P"
                a = "P"
            }
            "D" -> {
                ans += "D"
                a = "D"
            }
            "?" -> {
                if (a == "P") {
                    ans+="D"
                    a="D"
                } else {
                    ans += "P"
                    a="P"
                }
            }
        }
    }
    if (ans.takeLast(2) == "DP") {
        ans = ans.dropLast(2) + "DD"
    }
    println(ans)
}