#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#ifdef __unix__
#include <bits/stdc++.h>
#else
#include "bits\stdc++.h"
#endif
#include <vector>
#include <set>
#include <string>
#include <queue>
#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define SIZE 50

enum Muki{
  up,r,down,l
};

void draw_map(char map[][SIZE],int a,int x, int y,int muki) {
  int i;
  for(i=0;i<a;i++) {
    switch(muki) {
    case  up  : map[ x ][y+i] = '.'; break;
    case down : map[ x ][y-i] = '.'; break;
    case   r  : map[x+i][ y ] = '.'; break;
    case   l  : map[x-i][ y ] = '.'; break;
    }
  }
}

void print_map(char map[][SIZE]) {
  int i,j;
  for(i=0;i<SIZE;i++) {
    for(j=0;j<SIZE;j++) {
      if(map[j][i] == 0) continue;
      else printf("%c",map[j][i]);
    }
    puts("");
  }
}

int main() {
  /*
  cin.tie(0);
  ios::sync_with_stdio(false);
  */
  // char map[SIZE][SIZE] = {0};  
  // int x = 22 ,y = 22;
  int muki = down;
  int i,j,k;
  char s[20];
  // print_map(map);
  while(cin >> s) {
    if(strcmp(s,"Merry Christmas!") == 0)  break;
    int a = atoi(s);
    if(a == 20151224) cout << "F" << endl;
    else {
      // draw_map(map,a,x,y,muki);
      char c;
      if(a == 0) {       
        switch(rand() % 2) {
        case 0 : c = 'L'; break;
        case 1 : c = 'R'; break;
        }
      }
      else {
        switch(rand() % 3) {
        case 0 : c = 'F'; break;
        case 1 : c = 'L'; break;
        case 2 : c = 'R'; break;
        }
      }
      cout << c << endl;
      // print_map(map);
    }
  }

  return 0;
}