arr = gets.chomp.split('')
i = 0
switch = true
while i < arr.size
  if i%2 == 0 && arr[i] == "L"
    switch = false
  elsif i%2 == 1 && arr[i] == "R"
    switch = false
  end
  i+=1
end

if switch == true
  puts 'Yes'
else
  puts 'No'
end