package yukicoder;
import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		new Main().solve();
	}
	void solve(){
		Scanner sc=new Scanner(System.in);
		//F,B,L,R
		while(true){
			int r=(int)(Math.random()*4);
			if(r==0){
				System.out.println("F");
			}else if(r==1){
				System.out.println("B");
			}else if(r==2){
				System.out.println("L");
			}else if(r==3){
				System.out.println("R");
			}
			String s=sc.nextLine();
			if(s.equals("Merry Christmas!")){
				return;
			}
		}
	}
}