N=int(input())

A=[]

for i in range(N):
    
    a=int(input())
    
    A.append(a)
    
    
A.sort()


if N%2==0:
    
    answer=A[N/2]
    
else:
    
    answer=(A[N/2]+A[(N/2)+1])/2
    
    
print(answer)