content: fibo :: Integer -> Integer
  fibo 0 = 1
  fibo 1 = 1
  fibo n
     | n < 0 = fibo (-n)
     | n > 0 = fibo (n-1) + fibo (n-2)
  main :: IO()
  main = do
     putStrLn "Enter an integer: "
     number <- readLn :: IO Integer 
     putStrLn $ "Factorial of " ++ show number ++ " is " ++ show (fibo number)
  
  