#include <stdio.h>

int main() {
 int Ai[1000];
 int count = 0;
 int taihi = 0;
 int i, j;
 
 scanf("%d", &count);
 for (i = 0; i < count; i++) {
  scanf("%d", &Ai[i]);
 }
 
 for (i = 0; i < count - 1; i++) {
  for (j = i + 1; j < count; j++) {
   if(Ai[i] < Ai[j]) {
    taihi = Ai[i];
    Ai[i] = Ai[j];
    Ai[j] = taihi;
   }
  }
 }
 
 if (count % 2 == 0) {
  printf("%0.1f", (float)(Ai[count / 2 - 1]+Ai[count /2])/2);
 } else {
  printf("%0.1f\n", (float)Ai[count / 2]);
 }
}