S = gets.split('')
S_len = S.length
out = 0
for i in 0..S_len
    if i.even? then
        if S[i] == "L" then
            out += 1
        end
    else
        if S[i] == "R" then
            out += 1
        end
    end
end
if out == 0 then
    puts "Yes"
else
    puts "No"
end