#include <cstdio>
#include <cstdlib>

int compare_int(const void *a, const void *b)
{
  return *(int*)a - *(int*)b;
}

void FindMedian(int size, int *vector)
{
  if (size%2) {
    printf("%f\n",(float)vector[(size-1)/2]);
  } else {
    printf("%f\n",( (float)( vector[size/2]+vector[size/2-1] ) / 2 ) );
  }
}

int main(void)
{
  int length;
  int ary[1000];
  scanf("%d",&length);
  for(int i=0;i<length;i++){
    scanf("%d",&ary[i]);
  }
  qsort(ary, length, sizeof(int), compare_int);
  FindMedian(length, ary);
  return 0;
}