def main():

  N = int(input())
  number_list = list(map(int, input().split()))
  material_counts = len(number_list)
  number_list.sort()
  half_material_counts =  material_counts // 2
  if material_counts % 2 == 0:
    ans = (number_list[half_material_counts - 1] + number_list[half_material_counts]) / 2
    print(ans)

  else:
    ans = number_list[half_material_counts]
    print(ans)

if __name__ == '__main__':
  main()