<p>You are given an integer array <code>nums</code> with the following properties:</p> <ul> <li><code>nums.length == 2 * n</code>.</li> <li><code>nums</code> contains <code>n + 1</code> <strong>unique</strong> elements.</li> <li>Exactly one element of <code>nums</code> is repeated <code>n</code> times.</li> </ul> <p>Return <em>the element that is repeated </em><code>n</code><em> times</em>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre><strong>Input:</strong> nums = [1,2,3,3] <strong>Output:</strong> 3 </pre><p><strong>Example 2:</strong></p> <pre><strong>Input:</strong> nums = [2,1,2,5,3,2] <strong>Output:</strong> 2 </pre><p><strong>Example 3:</strong></p> <pre><strong>Input:</strong> nums = [5,1,5,2,5,3,5,4] <strong>Output:</strong> 5 </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 <= n <= 5000</code></li> <li><code>nums.length == 2 * n</code></li> <li><code>0 <= nums[i] <= 10<sup>4</sup></code></li> <li><code>nums</code> contains <code>n + 1</code> <strong>unique</strong> elements and one of them is repeated exactly <code>n</code> times.</li> </ul>