fib2 :: Int -> Int
fib2 n
  | n == 0 || n == 1 = n
  | otherwise = fib2 (n - 1) + fib2 (n - 2)
fib2 :: Int -> Int
fib2 n
  | n == 0 || n == 1 = n
  | otherwise = fib2 (n - 1) + fib2 (n - 2)
fib2 n
  | n == 0 || n == 1 = n
  | otherwise = fib2 (n - 1) + fib2 (n - 2)