# -*- coding: utf-8 -*-

def main():
    n = int(input())
    ns = tuple(sorted(map(int, input().split())))
    if n % 2 == 0:
        median = (ns[n // 2 - 1] + ns[n // 2]) / 2
    else:
        median = ns[n // 2]
    print(median)

if __name__ == '__main__':
    main()