ary = gets.chomp.split('')
ary_odd = []
ary_even = []
ary.each_with_index do |str, idx|
    if idx.odd?
        ary_odd << str
    else
        ary_even << str
    end
end

if !(ary_even.include?("L") || ary_odd.include?("R"))
    puts "Yes"
else
    puts "No"
end