3436. Fear Factoring

单点时限: 1.0 sec

内存限制: 256 MB

The Slivians are afraid of factoring; it’s just, well, difficult.

Really, they don’t even care about the factors themselves, just how much they sum to.

We can define $F(n)$ as the sum of all of the factors of $n$; so $F(6) = 12$ and $F(12) = 28$. Your task is, given two integers $a$ and $b$ with $a \le b$, to calculate

$$S = \sum_{a \le n \le b} F(n)$$

输入格式

The input consists of a single line containing space-separated integers $a$ and $b$ ($1 \le a \le b \le 10^{12}, b − a \le 10^6$).

输出格式

Print $S$ on a single line.

样例

Input
101 101
Output
102
Input
28 28
Output
56
Input
1 10
Output
87
Input
987654456799 987654456799
Output
987654456800
Input
963761198400 963761198400
Output
5531765944320

4 人解决,9 人已尝试。

5 份提交通过,共有 23 份提交。

8.4 EMB 奖励。

创建: 2 年,10 月前.

修改: 2 年,10 月前.

最后提交: 11 月前.

来源: Pacific Northwest 2017

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