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: Runtime Error)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner in = new Scanner(System.in);

		String s = in.next();
		char[] A = s.toCharArray();
		int N = A.length;
		for (int i = 0; i < N; i++) {

			if (A[i] != '?') {
				continue;
			}

			if (i == 0) {
				A[i] = A[i + 1] == 'P' ? 'D' : 'P';
			} else if (i == N - 1) {
				A[i] = 'D';
			} else {
				if (A[i - 1] == 'P') {
					A[i] = 'D';
				} else if (A[i + 1] == '?' || A[i + 1] == 'D') {
					A[i] = 'P';
				} else {
					A[i] = 'D';
				}
			}
		}
		System.out.print(new String(A));
		in.close();
	}

}