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: Accepted)

#include<bits/stdc++.h>
  using namespace std;
  #define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  #define endl "\n"
  #define ll long long
  #define int long long
  #define double long double
  #define max(a,b) (a>b?a:b)
  #define min(a,b) (a<b?a:b)
  #define mp make_pair
  #define pb push_back
  #define inf INT_MAX
  #define f first
  #define s second
  #define all(v) v.begin(), v.end()
  #define mod INT_MAX 
  const int MOD=1e9+7;
  const int N=2e5+2;
 
  
int32_t main(){
    /*#ifndef ONLINE_JUDGE
       freopen("in.txt","r",stdin);
       freopen("out.txt","w",stdout);
    #endif*/
       IOS
       string s;
       cin>>s;
       for(int i=0;i<s.length();i++)
       {
         if(s[i]=='?')
         {
            if(i and s[i-1]=='P')
            {
                s[i]='D';
            }
            else if(i+1<s.length() and s[i+1]=='D')
            {
               s[i]='P';
             
            }
            else if(i+1<s.length() and s[i+1]=='?')
            {
               s[i]='P';
               s[i+1]='D';
            }
             else
                {
                  s[i]='D';
                }
            }
         }
       
       cout<<s;
    return 0;
 }