N=int(input())
A=input().split()

for i in range(N):
    min=int(A[i])
    min_number=i
    for j in range(i+1,N):
        if min>=int(A[j]):
            min=int(A[j])
            min_number=j
    work=A[i]
    A[i]=A[min_number]
    A[min_number]=work
if N%2!=0:
    print(A[N//2])
else:
    print("{0:.1f}".format((int(A[N//2-1])+int(A[N//2]))/2))