package Yukicoder

/**
 * Created by hichikawa on 2015/11/02.
 */
fun main(args: Array<String>) {
    fun readLineIntArray() : List<Int> {
        val str = readLine() as String
        val arrStr = str.split(" ")
        val ret = arrStr.map { it.toInt() }
        return ret
    }
    fun readLineInt() : Int {
        val str = readLine() as String
        return str.toInt()
    }
    val num = readLineInt()
    val numList = readLineIntArray().sorted()
    if(num % 2 == 1) {
        println(numList[num/2])
    } else {
        println((numList[num/2-1].toDouble() + numList[num/2].toDouble())/2)
    }
}