ans [[n,d],xs] =
  let v = foldr (\ x a -> if x >= d then a + (x - d) else a) 0 xs
  in
    if v == 0 then "kusoge" else show(v)

main = do
  c <- getContents
  let i = map (map read) $ map words $ lines c :: [[Int]]
      o = ans i
  putStrLn o

