You are given an array A of strings. A move onto S consists of swapping any two even indexed characters of S, or any two odd indexed characters of S. Two strings S and T are special-equivalent if after any number of moves onto S, S == T. For example, S = "zzxy" and T = "xyzz" are special-equivalent because we may make the moves "zzxy" -> "xzzy" -> "xyzz" that swap S[0] and S[2], then S[1] and S[3]. Now, a group of special-equivalent strings from A is a non-empty subset of A such that: Every pair of strings in the group are special equivalent, and; The group is the largest size possible (ie., there isn't a string S not in the group such that S is special equivalent to every string in the group) Return the number of groups of special-equivalent strings from A. Example 1: Input: ["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 are 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: ["abc","acb","bac","bca","cab","cba"] Output: 3 Note: 1 <= A.length <= 1000 1 <= A[i].length <= 20 All A[i] have the same length. All A[i] consist of only lowercase letters.