Problem Description

Boris is the CEO of Rock Anywhere Transport (RAT) company, which specializes in supporting the music industry. Particularly, they offer discounted transportation for many popular rock bands. This time, Boris has to transport a large number of high-quality Mexican concert speakers from the北海 port to a distant inland capital. Due to the expected large volume of goods, Boris has to organize multiple trucks to ensure smooth transportation. The group of trucks transporting goods through the country is called a convoy.

Boris wants to transport all the goods in one convoy, leaving no speaker behind. Strict EU regulations require that in the case of large-scale transportation of audio technology equipment, all trucks in the convoy must carry exactly the same number of devices.

To meet all regulations, Boris wants to do some planning in advance, although he does not yet know the exact number of speakers, which greatly affects the choice of the number and capacity of trucks in the convoy. To check various scenarios, for each possible cargo capacity, Boris calculates the so-called "variability," which is the number of different convoys that can be created for that cargo capacity without violating the regulations. Two convoys are different if they consist of a different number of trucks.

For example, the variability of 6 speaker cargos is 4, because they can be evenly divided into 1, 2, 3, or 6 trucks.

Simplified Problem Statement

Given $l, r$, find the sum of the number of divisors for all numbers in the range $l \sim r$.

Input Format

The input contains a single line with two integers $N, M\ (1 \le N \le M \le 10^{12})$, representing the minimum and maximum number of speaker cargos.

Output Format

Output a single integer, representing the sum of variabilities for all cargo quantities between $N$ and $M$ inclusive.

Sample Input and Output

Sample Input #1

2 5

Sample Output #1

9

Sample Input #2

12 12

Sample Output #2

6

Sample Input #3

555 666

Sample Output #3

852

见题面 Input 部分

见题面 Output 部分