s = gets().chomp.split('')

is_easy = true

s_even = []
s_odd = []
s.each_with_index do |c, i|
  if i.odd?
    s_even.push(c)
  else
    s_odd.push(c)
  end
end

is_easy = false if s_even.include?('R')
is_easy = false if s_odd.include?('L')

puts is_easy ? 'Yes' : 'No'