dance = gets.chomp!
i = dance.length
judge = 0
for var in 1..i
  if var % 2 == 0
    if dance[var] == "L"
      judge += 1
    end
  else
    if dance[var] == "R"
      judge += 1
    end
  end
end

if judge == 0
  puts "Yes"
else
  puts "No"
end