#include<stdio.h>
#include<stdlib.h>
#include<string.h>

int main(){
	int *data,n,i,j,result;
	char *input,input_n[10],*point;
	
	fgets(input_n,sizeof(input_n),stdin);
	sscanf(input_n,"%d",&n);
	
	data=(int *)malloc(sizeof(int)*n);
	input=(char *)malloc(sizeof(char)*n*5+1);
	
	fgets(input,sizeof(char)*n*5+1,stdin);
	
	point=strtok(input," ");
	data[0]=atoi(point);
	
	for(i=1;i<n;i++){
		point=strtok(NULL," ");
		data[i]=atoi(point);
	}
	
	for(i=0;i<n-1;i++){
		for(j=0;j<n-1;j++){
			if(data[j]>data[j+1]){
				int save;
				save=data[j];
				data[j]=data[j+1];
				data[j+1]=save;
			}
			
		}
		
	}
	
	result=n%2;//nが奇数なら1 偶数なら0
	
	if(result==1){
		printf("%d\n",data[n/2]);
	}
	else if(result==0){
		double answer=(data[n/2-1]+data[n/2])/2.0;
		printf("%.1f\n",answer);
	}
	
	
	free(data);
	free(input);
	return 0;
}