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 C++ (GCC 9.2.1) (judge verdict: Runtime Error)

#include<bits/stdc++.h>
using namespace std;

int main(){
  string t;
  cin >> t;
  if(t.at(0) == '?' && t.at(1) == 'P')
    t.at(0) = 'D';
  else
    t.at(0) = 'P';
  for(int i = 1; i<t.size()-1; i++){
    if(t.at(i) == '?'){
      if(t.at(i+1) == 'D')
        t.at(i) = 'P';
      else if(t.at(i-1) == 'P')
        t.at(i) = 'D';
      else if(t.at(i+1) == '?')
        t.at(i) = 'P';
      else
        t.at(i) = 'D';
    }
  }
  if(t.at(t.size()-1) == '?')
    t.at(t.size()-1) = 'D';
  cout << t << endl;
}