s = gets.chomp.split('')

f = 1
s.length.times do |i|
  if i.even? && s[i] == 'L'
    print 'No'
    f = 0
    break
  elsif i.odd? && s[i] == 'R'
    print 'No'
    f = 0
    break
  end
end

print 'Yes' if f == 1