import Foundation

func readInts() -> [Int] {
    return readLine()!.split(separator: " ").map { Int($0)! }
}

let str=readLine()!
var flag=0

var i=0
for j in str{
  if i%2==1&&(j == "R"){flag-=1
                      break}
  if i%2==0&&(j == "L"){flag-=1
                      break}
  i+=1
}
if flag == -1 {print("No")}else{print("Yes")}