#include <iostream>
#include <string>
using namespace std;
int main(){
  int d=0,f_i=0,f_w=0;
  while(1){
    string s1,s2;getline(cin,s1);
    if(s1=="Merry Christmas!"){
      break;
    }
    if(s1=="20151224"){
      s2="F";
      cout<<s2<<endl;
      continue;
    }
    int a=stoi(s1);
    if(f_i==0 && a!=0){
      s2="F";
      cout<<s2<<endl;
      continue;
    } else if(f_i==0 && a==0){
      f_i=1;
    }
    if(f_w==0 && a==0){
      s2="R";
      cout<<s2<<endl;
      f_w=1;
      continue;
    } else if(f_w==0 && a!=0){
      s2="L";
      cout<<s2<<endl;
      f_w=1;
      continue;
    } else if(f_w!=0 && a==0){
      s2="R";
      cout<<s2<<endl;
      continue;
    } else if(f_w!=0 && a!=0){
      s2="F";
      cout<<s2<<endl;
      f_w=0;
      continue;
    }
  }
  return 0;
}