/* do rl, faster */
#include <stdio.h>
#include <stdlib.h>
typedef struct side {
   unsigned int cw, rw, *a ;
   int xlen, maxa ;
} side ;
int size ;
void init(side *a, int size) {
   a->a = (unsigned int *)calloc(sizeof(unsigned int), size) ;
   if (a->a == 0) {
      fprintf(stderr, "No memory.\n") ;
      exit(10) ;
   }
   a->xlen = 64 ;
   a->maxa = 1 ;
   a->cw = 0 ;
   a->rw = 1 ;
}
void advsame(side *a) {
   a->rw ^= (a->rw >> 1) | (a->cw << 31) ;
   a->cw ^= (a->cw >> 1) ;
}
void advlength(side *a) {
   a->cw ^= (a->cw << 1) | (a->rw >> 31) ;
   a->rw ^= a->rw << 1 ;
   a->xlen++ ;
}
void percolate(side *a, int gen) {
   /* should we grow the array? */
   int i, j, b, shift ;
   unsigned int w ;
   unsigned int afterw = 0 ;
   int haveafter = 0 ;
   shift = a->xlen & 31 ;
   if (a->xlen > 64) {
      w = a->rw >> shift ;
      if (shift != 0)
         w |= a->cw << (32 - shift) ;
      afterw = w ;
      haveafter++ ;
      a->maxa++ ;
      if (a->maxa >= size)
         exit(0) ;
      i = gen - 1 ;
      while (i) {
         b = i & - i ;
         i &= ~b ;
         if (b+b <= a->maxa)
            a->a[a->maxa-b] ^= a->a[a->maxa-b-b] ;
      }
      a->xlen -= 32 ;
   }
   /* now percolate down */
   b = gen & - gen ;
   for (j=0; j<b && j<=a->maxa; j++) {
      int st = b ;
      w = 0 ;
      while (st+j > a->maxa)
         st >>= 1 ;
      while (st > j) {
         w ^= a->a[a->maxa-j-st] ;
         st >>= 1 ;
      }
      a->a[a->maxa-j] ^= w ;
   }
   if (haveafter)
      a->a[a->maxa] = afterw ;
   /* now update cw, rw bits */
   if (shift == 0) {
      a->cw = a->a[a->maxa] ;
   } else {
      w = (1 << shift) - 1 ;
      a->cw = a->a[a->maxa] >> (32 - shift) ;
      a->rw = (a->rw & w) | (a->a[a->maxa] << shift) ;
   }
}
int main(int argc, char *argv[]) {
   side left, right ;
   int gen = 0, hgen=0, isr = 0 ;
   if (argc < 2 || sscanf(argv[1], "%d", &size) != 1)
      size = 10 ;
   if (size > 65000) {
      fprintf(stderr, "Can't do more than about 4B entries.\n") ;
      exit(10) ;
   }
   size *= 32768 ;
   init(&left, size) ;
   init(&right, size) ;
   while (1) {
      if (isr) {
         printf("R") ;
         if (right.rw & 1)
            isr = 0 ;
         advlength(&left) ;
         advsame(&right) ;
      } else {
         printf("L") ;
         if (left.rw & 1)
            isr = 1 ;
         advsame(&left) ;
         advlength(&right) ;
      }
      printf("\n") ;
      gen++ ;
      if (gen == 32) {
         hgen++ ;
         gen = 0 ;
         percolate(&left, hgen) ;
         percolate(&right, hgen) ;
      }
   }
}