#include <stdio.h>
#include <string.h>
int main(int argc,char *argv[]) {
 int i,j;
 char turns[1024]="R",append[1024],tmp[1024];
 for(i=0;i<atoi(argv[1]);i++) {
  strcpy(append,turns);
  strcat(turns,"R");
  for(j=0;append[j];j++) tmp[strlen(append)-j-1]=append[j]=='R'?'L':'R';
  tmp[j]=0;
  strcat(turns,tmp);
 }
 printf("F%s\n",turns);
}