fibonacci n
          | n == 0 = 0
          | n == 1 = 1
          | n == 2 = 1
          | otherwise = fibonacci (n - 1) + fibonacci (n - 2)
fibonacci n
          | n == 0 = 0
          | n == 1 = 1
          | n == 2 = 1
          | otherwise = fibonacci (n - 1) + fibonacci (n - 2)
fibonacci n
          | n == 0 = 0
          | n == 1 = 1
          | n == 2 = 1
          | otherwise = fibonacci (n - 1) + fibonacci (n - 2)