#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <iostream>
#include <set>
#include <map>
#include <vector>
#include <string>

#include <cmath>
#include <queue>
#include <stack>

using namespace std;

#define LL long long

const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, 1, -1};

LL mod(LL x, LL md) {
	return ((x % md) + md) % md;
}

class Mint {
public:
	static LL md;
	LL x;
	Mint(LL _x = 0) {
		x = mod(_x, md);
	}
	Mint(const Mint &y) {
		x = mod(y.x, md);
	}
};

void MintMyExgcd(LL a, LL b, LL &x, LL &y) {
	// solve equation ax + by = 1 (mod m)
	LL md = Mint::md;
	if (b == 0) {
		y = 0;
		x = 1;
		return ;
	}
	MintMyExgcd(b, a % b, x, y);
	LL t = y;
	y = mod(x - (a / b) * y, md);
	x = t;
}

LL MintNY(LL x) {
	if (x == 0) {
		return 1;
	}
	LL md = Mint::md;
	LL a, b;
	MintMyExgcd(x, md, a, b);
	while (a < 0) {
		a += md;
	}
	return a;
}

/* LL gcd(LL a, LL b) {
	if (b == 0) {
		return a;
	}
	return gcd(b, a % b);
} */

Mint operator+(Mint a, Mint b) {
	return Mint(mod(a.x + b.x, Mint::md));
}
Mint operator-(Mint a, Mint b) {
	return Mint(mod(a.x - b.x, Mint::md));
}
Mint operator*(Mint a, Mint b) {
	return Mint(mod(a.x * b.x, Mint::md));
}
Mint operator/(Mint a, Mint b) {
	Mint c = Mint(MintNY(b.x));
	return Mint(mod(a.x * c.x, Mint::md));
}

Mint operator-(Mint a) {
	return Mint(-a.x);
}
bool operator==(Mint a, Mint b) {
	return a.x == b.x;
}
bool operator!=(Mint a, Mint b) {
	return a.x != b.x;
}
bool operator>(Mint a, Mint b) {
	return a.x > b.x;
}
bool operator<(Mint a, Mint b) {
	return a.x < b.x;
}
bool operator>=(Mint a, Mint b) {
	return a.x >= b.x;
}
bool operator<=(Mint a, Mint b) {
	return a.x <= b.x;
}

void operator+=(Mint &a, Mint b) {
	a = a + b;
}
void operator-=(Mint &a, Mint b) {
	a = a - b;
}
void operator*=(Mint &a, Mint b) {
	a = a * b;
}
void operator/=(Mint &a, Mint b) {
	a = a / b;
}

ostream& operator<<(ostream &out, Mint a) {
	out << a.x;
	return out;
}

istream& operator>>(istream &in, Mint &a) {
	in >> a.x;
	return in;
}

Mint factorial(LL n) {
	if (n == 0) {
		return Mint(1);
	}
	Mint res = 1;
	for (LL i = 1; i <= n; ++i) {
		res *= i;
	}
	return res;
}
Mint multiRange(LL s, LL t) {
	Mint res = 1;
	for (LL i = s; i <= t; ++i) {
		res *= i;
	}
	return res;
}

Mint getC(LL n, LL k) {
	if (n - k < k) {
		return getC(n, n - k);
	}
	return multiRange(n - k + 1, n) / factorial(k);
}

Mint getA(LL n, LL k) {
	return multiRange(n - k + 1, n);
}

Mint countNonNegativeDivision(LL n, LL k) {
	return getC(n + k - 1, k - 1);
}
Mint countPositiveDivision(LL n, LL k) {
	if (n < k) {
		return 0;
	}
	if (k <= 0) {
		return 0;
	}
	return getC(n - 1, k - 1);
}
Mint quickMod(Mint a, LL b) {
	Mint res = 1;
	while (b > 0) {
		if (b % 2) {
			res *= a;
		}
		a *= a;
		b /= 2;
	}
	return res;
}

string t;

LL Mint::md = 1000000007;

char getC(int x) {
	if (x == 0) {
		return 'P';
	} else {
		return 'D';
	}
}

int main() {
	cin >> t;
	int n = t.length();
	vector<vector<int> > f(n);
	vector<vector<int> > c(n);
	for (int i = 0; i < n; ++i) {
		f[i] = vector<int>(2);
		c[i] = vector<int>(2);
		if (t[i] == 'P') {
			if (i == 0) {
				f[i][0] = 0;
				c[i][0] = -1;
			} else {
				if (f[i - 1][0] > f[i - 1][1]) {
					c[i][0] = 0;
					f[i][0] = f[i - 1][0];
				} else {
					c[i][0] = 1;
					f[i][0] = f[i - 1][1];
				}	
			}
			f[i][1] = -1;
			c[i][1] = -1;
			continue;
		}
		if (t[i] == 'D') {
			f[i][0] = -1;
			c[i][0] = -1;
			if (i == 0) {
				f[i][1] = 1;
			} else {
				if (f[i - 1][0] + 1 > f[i - 1][1]) {
					f[i][1] = 1 + f[i - 1][0] + 1;
					c[i][1] = 0;
				} else {
					f[i][1] = 1 + f[i - 1][1];
					c[i][1] = 1;
				}
			}
			continue;
		}
		// 0 for P, 1 for D
		if (i == 0) {
			f[i][0] = 0;
			f[i][1] = 1;
			c[i][0] = c[i][1] = -1;
		} else {
			if (f[i - 1][0] > f[i - 1][1]) {
				c[i][0] = 0;
				f[i][0] = f[i - 1][0];
			} else {
				c[i][0] = 1;
				f[i][0] = f[i - 1][1];
			}	
			if (f[i - 1][0] + 1 > f[i - 1][1]) {
				f[i][1] = 1 + f[i - 1][0] + 1;
				c[i][1] = 0;
			} else {
				f[i][1] = 1 + f[i - 1][1];
				c[i][1] = 1;
			}
		}
	}
	string res = "";
	int cur = n - 1, cc = -1;
	if (f[cur][0] > f[cur][1]) {
		cc = 0; 
	} else {
		cc = 1;
	}
	while (cur >= 0) {
		res.push_back(getC(cc));
		cc = c[cur][cc];
		cur -= 1;
	}
	// cout << res << endl;
	for (int i = n - 1; i >= 0; --i) {
		putchar(res[i]);
	}
	cout << endl;
	return 0;
}

Measured memory_bytes: 25780