long roadsAndLibraries(int n, int c_lib, int c_road, vector<vector<int>> cities) {
    if (cities.empty() || c_lib <= c_road) return (long)n * c_lib;

    map<int, stack<int>> cityMap;
    for (vector<int> road : cities) {
        int city1 = road[0], city2 = road[1];
        cityMap[city1].push(city2);
        cityMap[city2].push(city1);
    }

    vector<bool> visited(n + 1, false); 
    long libs = 0, rds = 0;

    for (int i = 1; i <= n; ++i) {
        if (!visited[i]) {
            libs++;
            stack<int> neighbors;
            neighbors.push(i);
            visited[i] = true;

            while (!neighbors.empty()) {
                int curr = neighbors.top();
                neighbors.pop();

                while (!cityMap[curr].empty()) {
                    int neighbor = cityMap[curr].top();
                    cityMap[curr].pop();

                    if (!visited[neighbor]) {
                        visited[neighbor] = true;
                        neighbors.push(neighbor);
                        rds++;
                    }
                }
            }
        }
    }

    return libs * c_lib + rds * c_road;
}