strs = gets.split("")
index = 1
ans = true

strs.each do |str|
    if index%2 == 0
        if str != 'L' && str != 'U' && str != 'D'
            ans = false
        end
    else
        if str != 'R' && str != 'U' && str != 'D'
            ans = false
        end
    end
    index += 1
end

if ans
    puts 'Yes'
else
    puts 'No'
end