# -*- coding: utf-8 -*-


n = int(input())
numbers = list(map(int, input().split()))
numbers.sort()
if 1 < n and len(numbers) % 2 == 1:
    print(numbers[(len(numbers) - 1) // 2])
else:
    center_front = numbers[(len(numbers) - 1) // 2]
    center_back = numbers[len(numbers) // 2]
    print((center_front + center_back) / 2)