str = gets.chomp.split("")
word = str.count.to_i
even = []
odd = []

for i in 0..word-1
  if i%2 == 0 || i == 0
    odd.push(str[i])
  else
    even.push(str[i])
  end
end

unless even.include?("R")
  unless odd.include?("L") 
  	puts "Yes"
  else
    puts "No"
  end
else
  puts "No"
end