main = interact $ unlines . map (show' . gamble) . read' . lines
 where
  read' ("0 0 0":_) = []
  read' (nmp:xs) = ((n, m, fromIntegral p), votes) : read' (drop n xs)
   where
    [n,m,p] = map read (words nmp)
    votes = map read (take n xs)
  show' r = case r of {Nothing -> "0"; (Just e) -> show e}

gamble :: ((Int, Int, Double), [Int]) -> Maybe Int
gamble ((n,m,p), vs)
 | vs!!(m-1) == 0 = Nothing
 | otherwise = Just $ floor $ fromIntegral (sum vs * 100) * ((100-p)/100) / fromIntegral (vs!!(m-1))