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>

#ifdef DEBUG
#define debug(x) cout << #x << ": " << x << endl
#else
#define debug(x)
#endif

#define int ll

#define REP(i, n) for(int i = 0; i < (n); i++)
#define REPS(i, n) for(int i = 1; i <= (n); i++)
#define ALL(v) (v).begin(), (v).end()

#define pb push_back
#define mp make_pair
#define mt make_tuple

using namespace std;

using ll = long long;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vs = vector<string>;
using vb = vector<bool>;
using vvi = vector<vi>;
using vvl = vector<vl>;

const int INF = 1e9;
const ll MOD = 1e9+7;

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

signed main()
{
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(20);

    string T; cin >> T;
    REP(i, T.length())
    {
        if(T[i] == '?') T[i] = 'D';
    }
    cout << T << endl;
}