static Boolean can_be_completed(Integer n, ArrayList<Integer> a, ArrayList<Integer> b) {
        //Build the graph
        Map<Integer, ArrayList<Integer>> adj_list = new HashMap<>();
        for (int course = 0; course < n; course++) {
            adj_list.put(course, new ArrayList<>());
        }
        for (int i = 0; i < a.size(); i++) {
            adj_list.get(b.get(i)).add(a.get(i));
        }
        
        // Caculating if we can complete the courses
        int[] visited = new int[n];
        for (int course = 0; course < n; course++) {
            if (visited[course] == 0) {
                if (!dfs(course, visited, adj_list)) {
                    return false;
                }
            }
        }
        
        return true;
    }

    static Boolean dfs(int course, int[] visited, Map<Integer, ArrayList<Integer>> adj_list) {
        visited[course] = 1;
        
        for (int courseNeighbor : adj_list.get(course)) {
            if (visited[courseNeighbor] == 0) {
                if (!dfs(courseNeighbor, visited, adj_list)) {
                    return false;
                }
            }
        }
        
        return true;
    }