<p>You are given two strings <code>a</code> and <code>b</code> of the same length. Choose an index and split both strings <strong>at the same index</strong>, splitting <code>a</code> into two strings: <code>a<sub>prefix</sub></code> and <code>a<sub>suffix</sub></code> where <code>a = a<sub>prefix</sub> + a<sub>suffix</sub></code>, and splitting <code>b</code> into two strings: <code>b<sub>prefix</sub></code> and <code>b<sub>suffix</sub></code> where <code>b = b<sub>prefix</sub> + b<sub>suffix</sub></code>. Check if <code>a<sub>prefix</sub> + b<sub>suffix</sub></code> or <code>b<sub>prefix</sub> + a<sub>suffix</sub></code> forms a palindrome.</p> <p>When you split a string <code>s</code> into <code>s<sub>prefix</sub></code> and <code>s<sub>suffix</sub></code>, either <code>s<sub>suffix</sub></code> or <code>s<sub>prefix</sub></code> is allowed to be empty. For example, if <code>s = "abc"</code>, then <code>"" + "abc"</code>, <code>"a" + "bc"</code>, <code>"ab" + "c"</code> , and <code>"abc" + ""</code> are valid splits.</p> <p>Return <code>true</code><em> if it is possible to form</em><em> a palindrome string, otherwise return </em><code>false</code>.</p> <p><strong>Notice</strong> that <code>x + y</code> denotes the concatenation of strings <code>x</code> and <code>y</code>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> a = "x", b = "y" <strong>Output:</strong> true <strong>Explaination:</strong> If either a or b are palindromes the answer is true since you can split in the following way: a<sub>prefix</sub> = "", a<sub>suffix</sub> = "x" b<sub>prefix</sub> = "", b<sub>suffix</sub> = "y" Then, a<sub>prefix</sub> + b<sub>suffix</sub> = "" + "y" = "y", which is a palindrome. </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> a = "xbdef", b = "xecab" <strong>Output:</strong> false </pre> <p><strong>Example 3:</strong></p> <pre> <strong>Input:</strong> a = "ulacfd", b = "jizalu" <strong>Output:</strong> true <strong>Explaination:</strong> Split them at index 3: a<sub>prefix</sub> = "ula", a<sub>suffix</sub> = "cfd" b<sub>prefix</sub> = "jiz", b<sub>suffix</sub> = "alu" Then, a<sub>prefix</sub> + b<sub>suffix</sub> = "ula" + "alu" = "ulaalu", which is a palindrome. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= a.length, b.length <= 10<sup>5</sup></code></li> <li><code>a.length == b.length</code></li> <li><code>a</code> and <code>b</code> consist of lowercase English letters</li> </ul>