<p>You are given the array <code>paths</code>, where <code>paths[i] = [cityA<sub>i</sub>, cityB<sub>i</sub>]</code> means there exists a direct path going from <code>cityA<sub>i</sub></code> to <code>cityB<sub>i</sub></code>. <em>Return the destination city, that is, the city without any path outgoing to another city.</em></p> <p>It is guaranteed that the graph of paths forms a line without any loop, therefore, there will be exactly one destination city.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> paths = [["London","New York"],["New York","Lima"],["Lima","Sao Paulo"]] <strong>Output:</strong> "Sao Paulo" <strong>Explanation:</strong> Starting at "London" city you will reach "Sao Paulo" city which is the destination city. Your trip consist of: "London" -> "New York" -> "Lima" -> "Sao Paulo". </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> paths = [["B","C"],["D","B"],["C","A"]] <strong>Output:</strong> "A" <strong>Explanation:</strong> All possible trips are: "D" -> "B" -> "C" -> "A". "B" -> "C" -> "A". "C" -> "A". "A". Clearly the destination city is "A". </pre> <p><strong>Example 3:</strong></p> <pre> <strong>Input:</strong> paths = [["A","Z"]] <strong>Output:</strong> "Z" </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= paths.length <= 100</code></li> <li><code>paths[i].length == 2</code></li> <li><code>1 <= cityA<sub>i</sub>.length, cityB<sub>i</sub>.length <= 10</code></li> <li><code>cityA<sub>i</sub> != cityB<sub>i</sub></code></li> <li>All strings consist of lowercase and uppercase English letters and the space character.</li> </ul>