{-# LANGUAGE ScopedTypeVariables #-}

import Control.Monad.ST
import Data.Array.ST
import Data.Array.Unboxed
import Data.Functor

primes :: Int -> Double -> UArray Int Double
primes n p = runSTUArray (newArray (2, n) 1.0 >>= sieve 2)
  where
    invp = 1 - p :: Double
    sup = n `div` 2 :: Int
    sieve :: forall s. Int -> STUArray s Int Double -> ST s (STUArray s Int Double)
    sieve i arr
      | i > sup = return arr
      | otherwise = erase (i + i) >>= sieve (i + 1)
      where
        erase :: Int -> ST s (STUArray s Int Double)
        erase j
          | j > n = return arr
          | otherwise =
             readArray arr j >>=
               writeArray arr j . (*invp) >>
                 erase (j + i)

main :: IO ()
main =
  words <$> getLine >>= \ (f0:f1:_) ->
    let n = read f0 :: Int
        p = read f1 :: Double
    in (putStrLn . show) (foldr (+) 0 (elems (primes n p)))