str = $stdin.gets.chomp

ans = "Yes"

for i in 0..str.size - 1
    if i % 2 == 1
        if str[i] != "L" and str[i] != "U" and str[i] != "D"
            ans = "No"
            break
        end
    else
        if str[i] != "R" and str[i] != "U" and str[i] != "D"
            ans = "No"
            break
        end
    end
end

puts ans