S = gets.chomp

ans1 = S.unpack('C*').each_with_index.any?{|s, idx| s == 'L'.ord && (idx % 2) == 0}
ans2 = S.unpack('C*').each_with_index.any?{|s, idx| s == 'R'.ord && (idx % 2) == 1}

puts (ans1 || ans2) ? 'No' : 'Yes'
