#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("unroll-loops")
//#pragma warning(disable : 4996)

#ifdef _MSC_VER
#include <intrin.h>
#define __builtin_popcount __popcnt
#define __builtin_popcountll __popcnt64
#endif

#include <limits.h>
#include <math.h>
#include <time.h>

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m - 1; i >= n; --i)
#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v, n) reverse(v, v + n);
#define VREVERSE(v) reverse(v.begin(), v.end())
#define ll long long
#define print(x) cout << (x) << '\n'
#define pe(x) cout << (x) << " "
#define DEBUG(x) cout << #x << ": " << x << endl
#define lb(v, n) lower_bound(v.begin(), v.end(), (n))
#define ub(v, n) upper_bound(v.begin(), v.end(), (n))
#define int long long
//#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v) REP(i, v.size()) cout << v[i] << ((i == v.size() - 1) ? "\n" : " ")
template <typename T1, typename T2> inline void chmin(T1& a, T2 b) {
	if (a > b) a = b;
}
template <typename T1, typename T2> inline void chmax(T1& a, T2 b) {
	if (a < b) a = b;
}
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef array<int, 3> arr3;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 998244353;
constexpr int MAX = 500050;
const double pi = acos(-1);
// constexpr double EPS = 1e-10;
constexpr ll LINF = 1e18 + 1;
constexpr int INF = 1e9 + 1;

int dp[200020][2];
char pre[200020][2];
void solve() {
	string S; cin >> S;
	int N = S.size();
	REP(i, N + 1)REP(j, 2)dp[i][j] = -1e9;
	REP(i, N) {
		if (i == 0) {
			if (S[i] == 'P')dp[0][0] = 0;
			else if (S[i] == 'D')dp[0][1] = 1;
			else {
				dp[0][0] = 0;
				dp[0][1] = 1;
			}
		}
		else {
			if (S[i] == 'P') {
				if (dp[i - 1][0] > dp[i - 1][1]) {
					dp[i][0] = dp[i - 1][0];
					pre[i][0] = 'P';
				}
				else {
					dp[i][0] = dp[i - 1][1];
					pre[i][0] = 'D';
				}
			}
			else if (S[i] == 'D') {
				if (dp[i - 1][0] + 1 > dp[i - 1][1]) {
					dp[i][1] = dp[i - 1][0] + 1;
					pre[i][1] = 'P';
				}
				else {
					dp[i][1] = dp[i - 1][1];
					pre[i][1] = 'D';
				}
			}
			else {
				//P
				if (dp[i - 1][0] > dp[i - 1][1]) {
					dp[i][0] = dp[i - 1][0];
					pre[i][0] = 'P';
				}
				else {
					dp[i][0] = dp[i - 1][1];
					pre[i][0] = 'D';
				}

				//D
				if (dp[i - 1][0] + 1 > dp[i - 1][1]) {
					dp[i][1] = dp[i - 1][0] + 1;
					pre[i][1] = 'P';
				}
				else {
					dp[i][1] = dp[i - 1][1];
					pre[i][1] = 'D';
				}
			}
		}
	}
	string ans;
	if (dp[N - 1][0] > dp[N - 1][1]) {
		ans += 'P';
		int sign = 0;
		for (int i = N - 1; i >= 1; i--) {
			ans += pre[i][sign];
			if (pre[i][sign] == 'P')sign = 0;
			else sign = 1;
		}
	}
	else {
		ans += 'D';
		int sign = 1;
		for (int i = N - 1; i >= 1; i--) {
			ans += pre[i][sign];
			if (pre[i][sign] == 'P')sign = 0;
			else sign = 1;
		}
	}
	VREVERSE(ans);
	print(ans);
}
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	//int q;
	//cin >> q;
	//while (q--)
	solve();
}


Measured memory_bytes: 7344