Exercise: minimum and maximum

Write a function min_max(nums) that returns a tuple (smallest, largest) of the smallest and the largest number in the list nums. Do not use the built-in functions min, max and sorted.

• min_max([3, 1, 4]) → (1, 4)
• min_max([-2, -8, 0]) → (-8, 0)
• min_max([7]) → (7, 7)

Constraints: the list holds 1 to 5 integers from -1000 to 1000; when there is one number, it is both the smallest and the largest; the result is a tuple, not a list.

Do not add extra imports unless the task says so explicitly.