<p>Given a balanced parentheses string <code>s</code>, return <em>the <strong>score</strong> of the string</em>.</p> <p>The <strong>score</strong> of a balanced parentheses string is based on the following rule:</p> <ul> <li><code>"()"</code> has score <code>1</code>.</li> <li><code>AB</code> has score <code>A + B</code>, where <code>A</code> and <code>B</code> are balanced parentheses strings.</li> <li><code>(A)</code> has score <code>2 * A</code>, where <code>A</code> is a balanced parentheses string.</li> </ul> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> s = "()" <strong>Output:</strong> 1 </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> s = "(())" <strong>Output:</strong> 2 </pre> <p><strong>Example 3:</strong></p> <pre> <strong>Input:</strong> s = "()()" <strong>Output:</strong> 2 </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 <= s.length <= 50</code></li> <li><code>s</code> consists of only <code>'('</code> and <code>')'</code>.</li> <li><code>s</code> is a balanced parentheses string.</li> </ul>