s = gets.chomp.split('')

easy = true
s.each_with_index do |value, index|
    if (index + 1) % 2 == 1
        if value == 'L'
            easy = false
            break
        end
    else
        if value == 'R'
            easy = false
            break
        end
    end
end

print(easy ? 'Yes' : 'No')