s = gets.chomp.split("")
result = true
s.size.times do |i|
  if i%2==0
    if s[i] == "L" || s[i] == "U" || s[i] == "D"
    else
      result = false
    end
  elsif i%2==1
    if s[i] == "R" || s[i] == "U" || s[i] == "D"
    else
      result = false
    end
  end
end
if result
  puts "Yes"
else
  puts "No"
end