#include <iostream>
using namespace std;

int main() {
    int N;
    cin >> N;
    int parity = 0;
    while (true) {
        if (parity) {
            cout << "R" << endl;
        } else {
            cout << "D" << endl;
        }
        int v;
        cin >> v;
        if (v != 0) {
            break;
        }
        parity ^= 1;
    }
}