import Data.Array.Unboxed (UArray, accumArray, elems)
import Control.Applicative ((<$>))

-- | Generates the sequence of prime numbers.
-- Based on <http://qiita.com/little_Haskeller/items/614a3ae20a517c19bb1f this article> .
primes2 :: Integral a => [a]
primes2 = map fromIntegral primes2'
    where
        primes2' = [2, 3, 5] ++ sieve2 5 7 (drop 2 primes2')
        sieve2 m s (p : ps) = [n | n <- ns, gcd m n == 1] ++ sieve2 (m * p) (p * p) ps
            where ns = [x + y | x <- [s, s + 6 .. p * p - 2], y <- [0, 4]]

primesTo :: Int -> [Int]
primesTo n = takeWhile (<= n) primes2

count :: Int -> Int -> Int
count n k = length $ filter (>= k) $ elems tb
    where
        tb = accumArray (+) 0 (2, n) [(p * i, 1) |
            p <- primesTo n, i <- [1 .. div n p]] :: UArray Int Int

main :: IO ()
main = do
    [n, k] <- map read . words <$> getLine
    print $ count n k