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 Python (3.8.2) (judge verdict: Wrong Answer)

import sys
import math
import itertools
s = input()
ans=''
for i in range(len(s)):
    if (i == len(s) - 1):
        if (s[i] == '?'):
            if (s[i - 1] == 'P'):
                ans += 'D'
                break
            else:
                ans += 'P'
                break
    else:
        break
    if (s[i] == '?'):
        if (s[i + 1] == 'D' or s[i+1]=='?'):
            ans += 'P'
        else:
            ans+='D'
    else:
        ans += s[i]
print(ans)