This classic guessing game is about carefully comparing a secret code with a player's guess. Write a function get_hint that counts bulls and cows for the strings secret and guess. A bull is a correct digit in the correct position, and a cow is a correct digit in the wrong position. Return the hint in the format xAyB, where x is the number of bulls and y is the number of cows.

def get_hint(secret: str, guess: str) -> str: