s = gets.chomp
odd_str = ["R", "U", "D"]
even_str = ["L", "U", "D"]
result = true
s.chars.each_with_index{|x, i|
  if i.odd?
    if odd_str.find{|y| y == x}.nil?
      result = false
    end
  else
  	if even_str.find{|y| y == x}.nil?
      result = false
    end
  end
}
if result
  puts "Yes"
else
  puts "No"
end