import sys
import math
#from queue import *
#import random
#sys.setrecursionlimit(int(1e6))
input = sys.stdin.readline
 
############ ---- USER DEFINED INPUT FUNCTIONS ---- ############
def inp():
    return(int(input()))
def inara():
    return(list(map(int,input().split())))
def insr():
    s = input()
    return(list(s[:len(s) - 1]))
def invr():
    return(map(int,input().split()))
################################################################
############ ---- THE ACTUAL CODE STARTS BELOW ---- ############

s=insr()

for i in range(0,len(s),2):
	if s[i]=='L':
		print("No")
		exit(0)

for i in range(1,len(s),2):
	if s[i]=='R':
		print("No")
		exit(0)

print("Yes") import sys sys import math math input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline def inp():
    return(int(input())) inp return(int(input())) int(input()) int input() input def inara():
    return(list(map(int,input().split()))) inara return(list(map(int,input().split()))) list(map(int,input().split())) list map(int,input().split()) map int input().split() ().split () input split def insr():
    s = input()
    return(list(s[:len(s) - 1])) insr s = input() s input() input return(list(s[:len(s) - 1])) list(s[:len(s) - 1]) list s[:len(s) - 1] s :len(s) - 1 len(s) - 1 len(s) len s 1 def invr():
    return(map(int,input().split()))
################################################################
############ ---- THE ACTUAL CODE STARTS BELOW ---- ############ invr return(map(int,input().split())) map(int,input().split()) map int input().split() ().split () input split s=insr() s insr() insr for i in range(0,len(s),2):
	if s[i]=='L':
		print("No")
		exit(0) i range(0,len(s),2) range 0 len(s) len s 2 if s[i]=='L':
		print("No")
		exit(0) s[i]=='L' s[i] s i 'L' print("No") print "No" exit(0) exit 0 for i in range(1,len(s),2):
	if s[i]=='R':
		print("No")
		exit(0) i range(1,len(s),2) range 1 len(s) len s 2 if s[i]=='R':
		print("No")
		exit(0) s[i]=='R' s[i] s i 'R' print("No") print "No" exit(0) exit 0 print("Yes") print "Yes" s=insr() insr() s def inara():
    return(list(map(int,input().split()))) def inara():
    return(list(map(int,input().split()))) inara def insr():
    s = input()
    return(list(s[:len(s) - 1])) def insr():
    s = input()
    return(list(s[:len(s) - 1])) insr def inp():
    return(int(input())) def inp():
    return(int(input())) inp input = sys.stdin.readline sys.stdin.readline input def invr():
    return(map(int,input().split()))
################################################################
############ ---- THE ACTUAL CODE STARTS BELOW ---- ############ def invr():
    return(map(int,input().split()))
################################################################
############ ---- THE ACTUAL CODE STARTS BELOW ---- ############ invr
import sys
import math
#from queue import *
#import random
#sys.setrecursionlimit(int(1e6))
input = sys.stdin.readline
 
############ ---- USER DEFINED INPUT FUNCTIONS ---- ############
def inp():
    return(int(input()))
def inara():
    return(list(map(int,input().split())))
def insr():
    s = input()
    return(list(s[:len(s) - 1]))
def invr():
    return(map(int,input().split()))
################################################################
############ ---- THE ACTUAL CODE STARTS BELOW ---- ############

s=insr()

for i in range(0,len(s),2):
	if s[i]=='L':
		print("No")
		exit(0)

for i in range(1,len(s),2):
	if s[i]=='R':
		print("No")
		exit(0)

print("Yes")
