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


if __name__ == "__main__":
    main()