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: Accepted)


import java.util.Scanner;

public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    char[] out = s.toCharArray();
    
    int index = 0;
    if(out[index] == '?') out[index] = 'D';
    index++;
    while(index < out.length) {
      if(out[index] == '?') {
        if(out[index-1] == 'P') {
          out[index] = 'D';
        }
        else {
          if(index < out.length - 1 && out[index+1] == '?') {
            out[index] = 'P';
            out[index+1] = 'D';
          }
          else {
            out[index] = 'D';
          }
        }
      }
      index++;
    }
    
    
    String outStr = new String(out);
    System.out.println(outStr);
    
  }
}