n = int(input())
a = [int(x) for x in input().split()]
a = a[:n]  # is needed?
a.sort()

if len(a) % 2 == 1:
    print(a[len(a) // 2 - 1])
else:
    print((a[len(a) // 2 - 1] + a[len(a) // 2]) / 2)