# 3436. Fear Factoring

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

### 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。