def main():
    count = int(input())
    items = [int(x) for x in input().split()]
    items.sort()    
    median = items[int(count / 2)]

    if count & 1 == 0:
        median = (median + items[int(count / 2) - 1]) / 2

    print(median)

if __name__ == '__main__':
    main()