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.*;
import javax.lang.model.util.ElementScanner6;
import java.lang.Math;

public class Main {

    public static void main(final String[] args) {
        final Scanner sc = new Scanner(System.in);

        // 入力
        String t = sc.next();

        // 処理
        char[] out = new char[t.length()];
        for(int i = 0; i < t.length(); i++){
            if(i == 0 && t.charAt(0) == '?'){
                if(t.length() == 1){
                    out[0] = 'D';
                } else if(t.charAt(1) == 'P'){
                    out[0] = 'D';
                } else {
                    out[0] = 'P';
                }
                 continue;
            }
            if(t.charAt(i) == '?'){
                if(out[i-1] == 'P'){
                    out[i] = 'D';
                } else {
                    out[i] = 'P';
                }
            } else {
                out[i] = t.charAt(i);
            }
        }

        // 出力
        System.out.println(out);
    }    
}