You are given an array of strings of the same length `words`.

In one move, you can swap any two even indexed characters or any two odd indexed characters of a string `words[i]`.

Two strings `words[i]` and `words[j]` are special-equivalent if after any number of moves, `words[i] == words[j]`.

- For example, `words[i] = "zzxy"` and `words[j] = "xyzz"` are special-equivalent because we may make the moves `"zzxy" -> "xzzy" -> "xyzz"`.

A group of special-equivalent strings from `words` is a non-empty subset of words such that:

- Every pair of strings in the group are special equivalent, and
- The group is the largest size possible (i.e., there is not a string `words[i]` not in the group such that `words[i]` is special-equivalent to every string in the group).

Return the number of groups of special-equivalent strings from `words`.

Example 1:

    Input: words = ["abcd","cdab","cbad","xyzz","zzxy","zzyx"]
    Output: 3
    Explanation:
    One group is ["abcd", "cdab", "cbad"], since they are all pairwise special equivalent, and none of the other strings is all pairwise special equivalent to these.
    The other two groups are ["xyzz", "zzxy"] and ["zzyx"].
    Note that in particular, "zzxy" is not special equivalent to "zzyx".

Example 2:

    Input: words = ["abc","acb","bac","bca","cab","cba"]
    Output: 3

Constraints:

- `1 <= words.length <= 1000`
- `1 <= words[i].length <= 20`
- `words[i]` consist of lowercase English letters.
- All the strings are of the same length.