import sys

try:
    import mydebug

    def dprint(*objects):
        print(*objects)
except:
    def dprint(*objects, sep='', end='\n'): pass

# d, p = [int(x) for x in input().split()]
n = int(input())
l = [int(x) for x in input().split()]
l.sort()

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