fun main() {
    val (n, m, k) = readln().split(" ").take(3).map { it.toInt() }
    val packages = readln().split(" ").take(n).map { it.toDouble() }.sortedDescending()
    val total = packages.sum()
    val max = packages.take(m + k).sum()
    println((max / total) * 100)
}