/* yukicoder My Practice
 * autoher: Leonarone  NEETSDKASU
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <math.h>

typedef long long ll;
typedef unsigned long long ull;

void solve(void);
int main(void) { solve(); return 0; }


void solve(void) {
    char str[30] = {0};
    int t = 0;
    
    for (;;) {
        gets(str);
        if (str[0] == 'M') break;
        if (str[3] > 0) {
            puts("F");
        } else {
            switch (t) {
            case 0:
                if (str[0] == '0')  {
                    puts("R");
                } else {
                    puts("F");
                    t = 1;
                }
                break;
            case 1:
                puts("R");
                t = 2;
                break;
            case 2:
                if (str[0] == '0') {
                    puts("L");
                } else {
                    puts("F");
                }
                t = 0;
                break;
            }
        }
        fflush(stdout);
    }
}