list = []

def palindrome? n
	a = n.to_s.split('').map {|x| x.to_i}
	b = 0
	i = 0
	a.each do |m|
		b += m*10**i
		i += 1
	end
	b == n ? n : nil
end

(100..999).each do |n|
	m = n
	while m > 99 
		list << m * n
		m -= 1
	end
end

puts list.sort.map{|x| palindrome? x}.compact.uniq.sort[-1]