Given an alphanumeric string `s`, return the second largest numerical digit that appears in `s`, or `-1` if it does not exist.

An alphanumeric string is a string consisting of lowercase English letters and digits.

Example 1:

    Input: s = "dfa12321afd"
    Output: 2
    Explanation: The digits that appear in s are [1, 2, 3]. The second largest digit is 2.

Example 2:

    Input: s = "abc1111"
    Output: -1
    Explanation: The digits that appear in s are [1]. There is no second largest digit.

Constraints:

- `1 <= s.length <= 500`
- `s` consists of only lowercase English letters and/or digits.