import math

N = int(input())
log = [ int(i) for i in input().split() ]

log = sorted(log)

if len(log) % 2 != 0:
    idx = math.floor(len(log) / 2)
    print(log[idx])
else:
    f_idx = len(log) // 2 - 1
    s_idx = len(log) // 2
    print((log[f_idx] + log[s_idx]) / 2)