N = int(input())
Arry_in = list(int(i) for i in input().split())
Arry_in.sort()

cen_N = int(N / 2)

if N % 2 == 0:
	print((Arry_in[cen_N - 1] + Arry_in[cen_N]) / 2)
else:
	print(Arry_in[cen_N])