N = int(input())
a = list(map(int, input().split()))

n = len(a)

a.sort()

if n % 2 == 1:
    median = a[n//2]
else:
    med_num1 = n//2
    med_num2 = n//2 + 1
    median = (a[med_num1 - 1] + a[med_num2 - 1]) / 2

print(median)