#include <stdio.h>

int main(void){
    int A[1000],N,x,i,d;
    scanf("%d",&N);
    for(i=0;i<N;i++){
        scanf("%d",A[i]);
    }
    for(i=0;i<N-1;i++){
        for(d=i;d<N;d++){
            if(A[i]>A[d]){
                A[i]=x;
                A[d]=A[i];
                A[i]=x;
            }
        }
    }
    if(N%2==0){
        printf("%.1f\n",(A[N/2-1]+A[N/2])/2.0);
    }
    else{
        printf("%.1f\n",(double)A[N/2]);
    }
    return 0;
}