main(n,i,j,t){int a[1000];scanf("%d",&n);for(i=0;i<n;i++)scanf("%d",&a[i]);for(i=0;i<n-1;i++)for(j=n-1;j>i;j--)if(a[j-1]>a[j]){t=a[j-1];a[j-1]=a[j];a[j]=t;}printf("%f",n%2?a[n/2]:(a[n/2-1]+a[n/2])/2.);}