import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)

n = int(readline())
a = sorted(list(map(int, readline().split())))
if n % 2 == 0:
    print((a[n // 2] + a[n // 2 - 1]) / 2)
else:
    print(a[n // 2])