You are given a string `s` representing a list of words. Each letter in the word has one or more options.

*   If there is one option, the letter is represented as is.
*   If there is more than one option, then curly braces delimit the options. For example, `"{a,b,c} "` represents options `[ "a ", "b ", "c "]`.

For example, if `s = "a{b,c} "`, the first character is always `'a'`, but the second character can be `'b'` or `'c'`. The original list is `[ "ab ", "ac "]`.

Return all words that can be formed in this manner, **sorted** in lexicographical order.

**Example 1:**

**Input:** s = "{a,b}c{d,e}f"
**Output:** \["acdf","acef","bcdf","bcef"\]

**Example 2:**

**Input:** s = "abcd"
**Output:** \["abcd"\]

**Constraints:**

*   `1 <= s.length <= 50`
*   `s` consists of curly brackets `'{}'`, commas `','`, and lowercase English letters.
*   `s` is guaranteed to be a valid input.
*   There are no nested curly brackets.
*   All characters inside a pair of consecutive opening and ending curly brackets are different.


def longestArithSeqLength(nums):
    n = len(nums)
    longest = 0
    dp = [{} for _ in range(n)]

    for i in range(n):
        for j in range(i):
            diff = nums[i] - nums[j]
            dp[i][diff] = dp[j].get(diff, 1) + 1
            longest = max(longest, dp[i][diff])

    return longest
