line = input()
n = int(line)
line_split = input().split()
a = [0]*n
for i in range(0,n):
    a[i] = int(line_split[i])
a.sort()
if n%2==0:
    m = int(n/2)
    print((a[m]+a[m+1])/2)
else :
    m = int(n/2)
    print(a[m])