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: Wrong Answer)

#include <stdio.h>
#include <string.h>
#define SIZE 200001
int main(){
  char t[SIZE];
  int len;
  int i;

  scanf("%s",t);
  len = strlen(t);

  for(i=0;i<len;i++){
    if(t[i]=='P' && t[i+1]=='?'){
      t[i+1]='D';
    }else if(t[i]=='D' && t[i+1]== '?' && t[i+2]=='D'){
      t[i+1]='P';
    }else if(t[i]=='D' && t[i+1]== '?' && t[i+2]=='P'){
      t[i+1]='D';
    }else if(t[i]=='D' && t[i+1]== '?' && t[i+2]=='?'){
      t[i+1]='P';
      t[i+2]='D';
    }else if(t[i]=='?' && t[i+1]=='?'){
      t[i]='P';
      t[i+1]='D';
    }else if(t[i]=='?' && t[i+1]=='P'){
      t[i]='D';
    }else if(t[i]=='?' && t[i+1]=='D'){
      t[i]='P';
    }
  }
  printf("%s\n",t);

  return 0;
}