백준 1037 약수 Python 수학 브론즈1

num = int(input())
arr = list(map(int,input().split()))
arr.sort()
# print(arr)
sum_v = 0
for i in range(num):
    sum_v += arr[i] * arr[-(i+1)]
sum_v = sum_v // (num)
print(sum_v)