Max Digit

Max Digit

You have a number and you need to determine which digit in this number is the biggest.

example

Input: A positive integer (int).

Output: An integer 0-9 (int).

Examples:

assert max_digit(0) == 0
assert max_digit(52) == 5
assert max_digit(634) == 6
assert max_digit(1) == 1
40