ary = gets.chomp.split("")
odd = ary.select.with_index{|e, i|
i % 2 == 0
}
even = ary.select.with_index{|e, i|
i % 2 == 1
}

if (odd.include?("L") || even.include?("R"))
    print "No"
else
    print "Yes"
end