input_array = gets.chomp.split("")
anser = []
input_array.each.with_index(1){|name,index|
  if index.odd?
   anser << (name =~ /R|U|D/)
  else
    anser << (name =~ /L|U|D/)
  end
  }

if anser.all?
	puts "Yes"
else
  	puts "No"
end