import Data.Char

primes = 2:3:[x | i<-[1..], j<-[-1,1], let x = 6*i+j, isPrime x]
 where isPrime n = null [i | i<-takeWhile (\x -> x^2 <= n) primes, mod n i == 0]

main = do
 [k,n] <- map read . words <$> getContents
 let ps = dropWhile (<k) (takeWhile (<=n) primes)
 print (ulhash [] (map hash ps))

ulhash acc [] = head acc
ulhash acc hps = ulhash (maxhash acc (dtp [] hps)) (tail hps)

hash p = (until (<10) (sum . map digitToInt . show) p, p) 

dtp acc [] = map snd (reverse acc)
dtp acc ((h,p):hps)
 | lookup h acc /= Nothing = map snd (reverse acc)
 | otherwise = dtp ((h,p):acc) hps

maxhash hps1 hps2
 | length hps1 > length hps2 = hps1
 | length hps1 < length hps2 = hps2
 | otherwise = max hps1 hps2