mod = 998244353
bsize = 500


def main():
    import sys
    from bisect import bisect_left
    input = sys.stdin.readline

    N = int(input())
    A = list(map(int, input().split()))

    A.sort()
    cs = [0]
    for a in A:
        cs.append(cs[-1] + a)
    ans = 0
    mod_list = [[0] * i for i in range(bsize + 1)]
    for a in A:
        for m in range(1, bsize + 1):
            if a > m:
                mod_list[m][a % m] += 1
    for i, a in enumerate(A):
        ans += a * (N - i - 1)
        if a <= bsize:
            tmp = 0
            for d in range(a):
                tmp += d * mod_list[a][d]
            ans -= tmp
        else:
            for k in range(1, 2 * 10 ** 5):
                if a * k > 2 * 10 ** 5:
                    break
                l = bisect_left(A, a * k)
                r = bisect_left(A, a * (k + 1))
                if l != r:
                    tmp = cs[r] - cs[l]
                    tmp -= a * k * (r - l)
                    ans -= tmp
    print(ans)


if __name__ == '__main__':
    main()