import System.Random
import Control.Monad

total = 100000

main = do xs <- replicateM total runTest
          print $ (sum xs) / fromIntegral total

runTest = do g0 <- newStdGen
             let list = randomRs (0,1) g0 :: [Int]
             let choices = takeWhile (==0) list
             return $ 100 / fromIntegral (length choices + 1)