/*No.275 中央値を求めよ*/
import java.util.*;
public class No275 {
    public static void main(String[] args) {
    	short N;
    	float median;
		try(Scanner input =new Scanner(System.in)){
			N=input.nextShort();
			short data []= new short[N];
			for(short i=0;i<data.length;i++){
				data[i]=input.nextShort();
			}
			Arrays.sort(data);
			if(N%2!=0){
				median=data[data.length/2];
			}else{
				median=(data[data.length/2]+data[data.length/2-1])/2f;
			}
			System.out.println(median);
		}catch(Exception e){
			e.printStackTrace();
		}
    }
}