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

for i in range(N):
    min=A[i]
    min_number=i
    flag=True
    for j in range(i+1,N):
        if min>=A[j]:
            min=A[j]
            min_number=j
            flag=False
    if flag==True:
        break
    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))