module Main where
 
main :: IO ()
main = do
  [a, b, _, d] <- getIntList
  if d >= 10 then
    putStrLn "Impossible"
  else do
    putStrLn "Possible"
    print $ solve a b
 
solve :: Int -> Int -> Int
solve a b = go 0 1 a b
  where
  go acc _ 0 0 = acc
  go acc x a b | a + b <= 100 = acc + x * (100 * a + 50 * b)
  go acc x a 0 = go (acc + 100 * 100 * x) (x * 2) (a - 100) 0
  go acc x a b | b < 100   = let b' = 100 - b
                             in  go (acc + (100 * b' + 50 * b) * x) (x * 2) (a - b') 0
               | otherwise = go (acc + 50 * 100 * x) (x * 2) a $ b - 100
 
getIntList :: IO [Int]
getIntList = map read . words <$> getLine