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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.Scanner;

/*

*/

public class Main {
    public static void main(String[] args){

        Scanner sc = new Scanner(System.in);
        String t = sc.next();

        String[] temp = t.split("");

        String[] ans = new String[t.length()];
        String flg = "";

        // flgはひとつ前の文字列PかDかを保持
        // pointは判定文字を保持
        for (int i = 0; i < t.length(); i++) {
            String point = temp[i];
            if (!point.equals("?")) {
                flg = point;
            } else {
                if (i == 0) {
                    flg = "D";
                    flg = point;
                    ans[i] = flg;
                    continue;
                }
                if (i != t.length() -1) {
                    if (flg.equals("P") && temp[i+1].equals("P")) {
                        flg = "D";
                    } else if (flg.equals("P") && temp[i+1].equals("D")) {
                        flg = "D";
                    } else if (flg.equals("D") && temp[i+1].equals("D")) {
                        flg = "P";
                    } else if (flg.equals("D") && temp[i+1].equals("P")) {
                        flg = "D";
                    }    
                }
                if (i == t.length() -1) {
                    if (flg.equals("P")) {
                        flg = "D";
                    } else if (flg.equals("D")) {
                        flg = "P";
                    }    
                }
            }
            ans[i] = flg;
        }

        String answer = String.join("", ans);
        System.out.println(answer);
    }
}