import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Scanner;


public class Main_yukicoder331 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Printer pr = new Printer(System.out);

        int ph = 0;
        while (true) {
        	String s = sc.nextLine();

        	if (s.equals("Merry Christmas!")) {
        		break;
        	}

        	int f = Integer.parseInt(s);

//        	pr.printf("f ph prev d %d %d %d %d\n", f, ph, prev, d);

        	if (f == 20151224) {
        		pr.println("F");
        		pr.flush();
        		ph = 99;
        		continue;
        	}

        	if (ph == 0) {
        		if (f == 0) {
        			ph = 1;
        			pr.println("R");
        			pr.flush();
        		} else {
        			pr.println("F");
        			pr.flush();
        		}
        	} else if (ph == 1) {
        		pr.println("L");
        		pr.flush();
        		ph = 2;
        	} else if (ph == 2) {
        		if (f == 0) {
        			pr.println("R");
        			pr.flush();
        			ph = 3;
        		} else {
        			pr.println("F");
        			pr.flush();
        			ph = 1;
        		}
        	} else if (ph == 3) {
        		if (f == 0) {
        			pr.println("R");
        			pr.flush();
        			ph = 1;
        		} else {
        			pr.println("F");
        			pr.flush();
        			ph = 1;
        		}
        	} else {
        		pr.println("F");
        		pr.flush();
        	}
        }

        pr.close();
        sc.close();
    }

    /*
	@SuppressWarnings("unused")
	private static class Scanner {
		BufferedReader br;
		Iterator<String> it;

		Scanner (InputStream in) {
			br = new BufferedReader(new InputStreamReader(in));
		}

		String next() throws RuntimeException  {
			try {
				if (it == null || !it.hasNext()) {
					it = Arrays.asList(br.readLine().split(" ")).iterator();
				}
				return it.next();
			} catch (IOException e) {
				throw new IllegalStateException();
			}
		}

		int nextInt() throws RuntimeException {
			return Integer.parseInt(next());
		}

		long nextLong() throws RuntimeException {
			return Long.parseLong(next());
		}

		float nextFloat() throws RuntimeException {
			return Float.parseFloat(next());
		}

		double nextDouble() throws RuntimeException {
			return Double.parseDouble(next());
		}

		void close() {
			try {
				br.close();
			} catch (IOException e) {
//				throw new IllegalStateException();
			}
		}
	}
	*/

	private static class Printer extends PrintWriter {
		Printer(PrintStream out) {
			super(out);
		}
	}
}