class AccumulateSum:
    def __init__(self, array):
        self.n = len(array)
        self.cumsum = [0] * (self.n + 1)
        for i, val in enumerate(array):
            self.cumsum[i + 1] = self.cumsum[i] + val

    def sum(self, l, r):
        return self.cumsum[r] - self.cumsum[l]


n = int(input())
a = list(map(int, input().split()))


a = sorted(a, reverse=True)


cnts = [0] * (10 ** 6)
for i in range(n):
    cnts[a[i]] += 1
cnts_ru = AccumulateSum(cnts)

vals = [0] * (10 ** 6)
for i in range(n):
    vals[a[i]] += a[i]
vals_ru = AccumulateSum(vals)


ans = 0
for i in range(n):
    ans += i * a[i]


for i in range(n):
    val = a[i]
    for res in range(1, int((val + 1) ** 0.5) + 1):
        l = (val) // (res + 1) + 1
        r = min((val // res) + 1, val)
        ans -= cnts_ru.sum(l, r) * val - vals_ru.sum(l, r) * res

    for waru in range(1, l):
        if cnts[waru] == 1:
            ans -= val - waru * (val // waru)
print(ans)