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 Go (1.14.1) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var sc = bufio.NewScanner(os.Stdin)

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func main() {
	//sc.Split(bufio.ScanWords)
	buf := make([]byte, 10000)
	sc.Buffer(buf, 200010)
	sc.Scan()
	t := sc.Text()
	//a := strings.Split(t, "")

	//if a[len(a)-1] == "?" { a[len(a)-1] = "D"}
	//if len(a) < 2 {
	//	fmt.Println(strings.Join(a, ""))
	//	return
	//}

	//for i := len(a)-2; i >= 0; i-- {
	//	if a[i] != "?" { continue }
	//	if a[i-1] == "D" {
	//		a[i] = "P"
	//	} else {
	//		a[i] = "D"
	//	}
	//}

	fmt.Println(strings.ReplaceAll(t, "?", "D"))
}

func slicePrint(s []int) {
	for i, v := range s {
		if i != 0 {
			fmt.Printf(" ")
		}
		fmt.Printf("%v", v)
	}
	fmt.Println("")
}

func abs(n int) int {
	if n < 0 {
		return -n
	}
	return n
}