S = gets.chomp.split("")
result = "Yes"
for i in 0..(S.length - 1) do
  if (i + 1).odd? then
    # odd  => except for L
    result = "No" if S[i] == "L"
  else
    # even => except for R
    result = "No" if S[i] == "R"
  end
end

puts result