{- |

Module : $EmptyHeader$

Description : <optional short description entry>

Copyright : (c) <Authors or Affiliations>

License : GPLv2 or higher

Maintainer : <email>

Stability : unstable | experimental | provisional | stable | frozen

Portability : portable | non-portable (<reason>)

<optional description>

-}

fibon :: Int -> Int

fibon n = if n == 0 then 1 else if n == 1 then 1 else fibon (n - 1) + fibon (n - 2)