Return the number of distinct non-empty substrings of text that can be written as the concatenation of some string with itself (i.e. it can be written as a + a where a is some string). Example 1: Input: text = "abcabcabc" Output: 3 Explanation: The 3 substrings are "abcabc", "bcabca" and "cabcab". Example 2: Input: text = "leetcodeleetcode" Output: 2 Explanation: The 2 substrings are "ee" and "leetcodeleetcode". Constraints: 1 <= text.length <= 2000 text has only lowercase English letters.