local s = io.read()
local n = #s
local ret = true
for i = 1, n do
  if i % 2 == 0 then
    if s:sub(i, i) == "R" then
      ret = false
      break
    end
  else
    if s:sub(i, i) == "L" then
      ret = false
      break
    end
  end
end
print(ret and "Yes" or "No")
