#124 백준 파이썬 [1037] 약수

https://www.acmicpc.net/problem/1037

 

 

#Solution

N = int(input())
gcd_list = list(map(int, input().split()))
gcd_list = sorted(gcd_list)
answer = 0

for i in range(len(gcd_list)):
    answer += gcd_list[i] * gcd_list[-i-1]

print(answer//len(gcd_list))