N = int(input())
A = list(map(int, input().split()))
A.sort()
if N % 2 == 0:
    median1 = N // 2 - 1 
    median2 = N // 2 
    median = (A[median1] + A[median2]) / 2
    print(median)
else:
    median1 = N // 2
    median = A[median1]
    print(median)