## OPMODULO - "Operation - Modulo"

Mahmud solved some easy math problems from SPOJ and called himself king of number theory. GodFather GodMATHer Rashad heard it and got angry, so he kidnapped Mahmud. Rashad gave him a task called "Operation - Modulo". Mahmud must solve this task, you know what will happen otherwise ;(. In the Operation - Modulo, we define a function f(n) = (n mod 1) + (n mod 2) + (n mod 3) + ... + (n mod n), where n mod x donates the remainder when dividing n by x. Rashad interests with integers n such that f(n)=f(n-1), so he gave Mahmud two numbers L and R, and demands him to find the sum of all integers n such that L ≤ n ≤ R and f(n)=f(n-1).

Input

First and the only line of input contains two positive integers, L and R (1 ≤ L ≤ R ≤ 1018).

Output

Print the demanded sum in one line.

### Example

```Input:1 3
```
```Output:3
```

Note:

I hope you proved your solution before submitting it :) hodobox: 2019-05-26 03:19:35 @drdrunkenstein, so you see that f(1)=f(0) and f(2)=f(1), so both n=1 and n=2 satisfy f(n)=f(n-1), and the answer is the sum of all such numbers, in this case 1+2 = 3. drdrunkenstein: 2019-04-24 16:58:39 Can someone explain me the test cases? f(0)=0 f(1)=1%1=0 f(2)=2%1 + 2%2=0 f(3)=3%1 + 3%2 + 3%3=1 So in range 1 to 3 there are only two values of n for which f(n)=f(n-1) i.e. n=1 & n=2. So how does the test case has answer 3? sandeep48: 2018-12-25 15:01:15 try to figure out the sequence of no. nice problem ,+1 kushagrasri: 2018-11-13 08:04:20 once you get the idea, the problem is super easy. plus, everything fits in long long int. a very interesting problem. ac in one go! abhishak69: 2018-10-06 13:59:40 can you give more testcase prakash1108: 2018-03-17 14:22:10 nice problem @barishnamazov Re: Thanks Last edit: 2018-03-18 16:29:18 julkas: 2018-03-17 10:58:21 @barishnamazov Good problem, Успехов! Re: Thanks :) Last edit: 2018-03-17 13:28:39 mahmud2690: 2018-03-15 19:50:30 nice problem bratan. +1 Re: Thanks bratan <3 Last edit: 2018-03-15 19:56:59