/**
 * Given two sets of cities, find the common cities between them.
 *
 * @param cities1 A set of cities.
 * @param cities2 Another set of cities.
 * @return A set containing the common cities between cities1 and cities2.
 */
fun getCommonCities(cities1: Set<String>, cities2: Set<String>): Set<String> {

    val commonCities = mutableSetOf<String>()

    for (city in cities1) {
        if (city in cities2) {
            commonCities.add(city)
        }
    }

    return commonCities
}
/**
 * Given two sets of cities, find the common cities between them.
 *
 * @param cities1 A set of cities.
 * @param cities2 Another set of cities.
 * @return A set containing the common cities between cities1 and cities2.
 */
fun getCommonCities(cities1: Set<String>, cities2: Set<String>): Set<String> {
/**
 * Given two sets of cities, find the common cities between them.
 *
 * @param cities1 A set of cities.
 * @param cities2 Another set of cities.
 * @return A set containing the common cities between cities1 and cities2.
 */
fun getCommonCities(cities1: Set<String>, cities2: Set<String>): Set<String> {

    val commonCities = mutableSetOf<String>()

    for (city in cities1) {
        if (city in cities2) {
            commonCities.add(city)
        }
    }

    return commonCities
}