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