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

#define ll long long
#define ld long double

const int MOD = 1e9 + 7;
#define INF 2e9

#define REPS(i, a, n) for (ll i = (a); i < (ll)(n); ++i)
#define REP(i, n) REPS(i, 0, n)
#define RREP(i, n) REPS(i, 1, n + 1)
#define DEPS(i, a, n) for (ll i = (a); i >= (ll)(n); --i)
#define DEP(i, n) DEPS(i, n, 0)
#define EACH(i, n) for (auto&& i : n)

#define MATCH(_str, _ptn) regex_match(_str, regex(_ptn))
#define REPLACE(_str, _ptn, _replacement) regex_replace(_str, regex(_ptn), _replacement)

# define pb push_back

# define INIT() cin.tie(0); ios::sync_with_stdio(false); cout << fixed << std::setprecision(20)

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

string s;
int main() {
    INIT();
    cin >> s;
    char prev = 'D';
    s = REPLACE(s, "\\?D", "PD");
    for(ll i = 0; i< s.size(); i++) {
        if(s[i] == '?') {
            ll j;
            for(j = i; j < s.size(); j++) {
                if(s[j] != '?') {
                    break;
                }
            }
            j--;
            for(;j >= i; j--) {
                if(j == s.size() - 1) {
                    s[j] = 'D';
                } else if(s[j + 1] == 'D') {
                    s[j] = 'P';
                } else {
                    s[j] = 'D';
                }
            }
        }
        cout << s[i];
    }
    return 0;
}