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: Time Limit Exceeded)

import java.util.*;
import java.math.*;
import java.lang.*;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String t = sc.next();
    int n = t.length();
    String[] data = new String[n];

    int l = 0;

    String s = "";

    for (int i = 0; i < n; i++) {
      data[i] = t.substring(i,i+1);
      if (data[i].equals("?")) {
        data[i] = "D";
      }
      s += data[i];
    }

    // int count = 0;
    //
    // for (int i = 0; i < n; i++) {
    //   String k = s.substring(i,i+1);
    //   if (k.equals("D")) {
    //     count++;
    //   }
    // }
    //
    // for (int i = 0; i < n-1; i++) {
    //   String k = s.substring(i,i+2);
    //   if (k.equals("PD")) {
    //     count++;
    //   }
    // }

    System.out.println(s);

  }

}