#include <stdio.h>
int main() {
  int A[1000] = {0}, i, j, N, tmp;
  scanf("%d", &N);
  for (i = 0; i < N; i++) {
    scanf("%d", &A[i]);
  }
  for (i = 0; i < N; i++) {
    for (j = i+1; j < N; j++) {
      if (A[i] > A[j] && j != N) {
        tmp =  A[i];
        A[i] = A[j];
        A[j] = tmp;
      }
    }
  }
  if (N%2 == 1) {
    printf("%d\n", A[N/2]);
  } else {
    printf("%.1f\n", (double)((A[N/2-1]+A[N/2]))/2);
  }
  return 0;
}