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.*;

public class Main {

    public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String text = sc.nextLine();
		StringBuilder sb = new StringBuilder();
		sb.append(text);
		int num = 1;
		for (int a = text.length()-1; a>0; a--) {
			char c = sb.charAt(a);
			if (num == 1) {
				if (c == '?') {
					sb.setCharAt(a, 'D');
				}
				num++;
			} else {
				char c1 = sb.charAt(a+1);
				if (c1 == 'P') {
					sb.setCharAt(a, 'D');
				} else {
					sb.setCharAt(a, 'P');
				}
			}
		}
		System.out.println(sb.toString());
	}
}