import Control.Applicative ((<$>))
import Control.Monad (when, foldM, forM_)
import Data.Vector.Unboxed.Mutable (IOVector, STVector)
import qualified Data.Vector.Unboxed.Mutable as VM

main :: IO ()
main = do
  [sn, sp] <- words <$> getLine
  solve (read sn) (read sp) >>= print

solve :: Int -> Double -> IO Double
solve n p = do
  ev <- VM.replicate (n+1) 1.0 :: IO (IOVector Double)
  forM_ [2 .. n] $ \i -> do
    forM_ [2*i, 3*i .. n] $ \j -> do
      x <- VM.read ev j
      VM.write ev j (x * (1.0 - p))
  foldM (\e i -> do
            x <- VM.read ev i
            return $ e + x
        ) 0.0 [2..n]