s = gets.chomp!.to_s

ls = s.split("")
#p ls

for i in 0..ls.length do
  if i%2 == 0
    #偶数番んめ
    if ls[i] == "L"
      print("No\n")
      exit
    end
  else
    #奇数番目
    if ls[i] == "R"
      print("No\n")
      exit
    end
  end
end
print("Yes\n")