open class Noun(val n: String)
open class City(val c: String) : Noun(c)
open class Cabrobro(val j: String) : City(j)

fun <T> copyData(source: MutableList<T>, destination: MutableList<in T>) {
    for (item in source) {
        destination.add(item)
    }
}

fun main(args: Array<String>) {
    val source= mutableListOf(City("c1"), City("c2"), City("c3"))
    val destination= mutableListOf<Cabrobro>()
    copyData(source, destination)
}