import Control.Monad
import Text.Printf
    
main = do
  [p, c] <- liftM (map read . words) getLine
  let
      s = sum [2,3,5,7,11,13] ^ p * sum [4,6,8,9,10,12] ^ c
      e :: Double
      e = fromIntegral s / (6 ** fromIntegral (p + c))
   in printf "%.13f\n" e