from itertools import accumulate
from bisect import bisect_left
n = int(input())
a = sorted(map(int, input().split()))
b = list(accumulate(a[::-1]))
m = max(a)
ans = 0
for i, v in enumerate(a[:-1]):
    ans += 2*v*(n-i-1)-b[n-i-2]
    for j in range(2, m//v+1):
        ans += v*(n-bisect_left(a, v*j))
print(ans)