#include<iostream>
using namespace std;

int main(){
	/*数字の数*/
	int number;
	cin >> number;

	/*ソート前の配列*/
	int loose[number];
	for(int i=0; i<number; i++){
		cin >> loose[i];
	}

	/*ソート後の配列*/
	int low=1001, locate;
	int sorted[number];
	for(int a=0; a<number; a++){
		for(int b=0; b<number; b++){
			if(loose[b] < low){
				low = loose[b];
				locate = b;
			}
		}
		sorted[a] = loose[locate];
		loose[locate] = 1001;
		low = 1001;
	}

	/*中央値を表示*/
	if(number%2 == 0)
		cout << (sorted[(number/2)-1]+sorted[(number/2)]) / 2.0 << endl;
	else
		cout << sorted[(number/2)] << endl;

}