最大数

import sys
sys.setrecursionlimit(3000)


flag_num = 0
str_list = [chr(x) for x in range(65, 71)] + [str(y) for y in range(0, 10)]
target_list = []


class Solution:
    def solve(self, s):
        global flag_num
        pointer1 = pointer2 = flag_num
        while pointer1 < len(s) and s[pointer1] == '0':
            flag_num += 1
            pointer1 = pointer2 = flag_num
        while pointer2 < len(s) - 1 and s[pointer2] in str_list:
            pointer2 += 1
        if pointer1 != pointer2:
            target_list.append(s[pointer1:pointer2])
        if flag_num < len(s):
            flag_num = pointer2 + 1
            self.solve(s)
        res = max(target_list, key=lambda item: int(item, 16))
        return int(res, 16)