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;
using ll=long long;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define inf 1001001001001001001
#define mod 1000000007
#define mod2 998244353
#define pi acos(-1)
#define all(v) v.begin(),v.end()

ll gcd(ll a,ll b){
    if(b>a) swap(a,b);
    if(b==0) return a;
    return gcd(b,a%b);
}
ll lcm(ll a,ll b){
    ll g=gcd(a,b);
    return a/g*b;
}
ll rep_jijo(ll n,ll x){
    if(x==0) return 1;
    if(x%2==0){
        ll t=rep_jijo(n,x/2);
        return t*t;
    }
    return n*rep_jijo(n,x-1);
}

int main(){
    string t;
    cin >> t;
    string ans=t;
    int len = t.size();
    rep(i,len){
        if(t[i]=='?')t[i]='D';
    }
    cout << t << endl;
    
    return 0;
}