fun main() {
    val builder = StringBuilder()

    val n = readInputLine().toInt()

    val arr = readInputLine().split(" ").map { it.toInt() }.sorted().toIntArray()

    builder.appendln(
        if (n % 2 == 1) {
            arr[n / 2]
        } else {
            (arr[n / 2 - 1] + arr[n / 2]).toDouble() / 2.0
        }
    )

    print(builder.toString())
}

fun readInputLine(): String {
    return readLine()!!
}