D - Remainder Reminder

Time Limit: 2 sec / Memory Limit: 256 MB

### 制約

• 1 \leq N \leq 10^5
• 0 \leq K \leq N-1
• 入力は全て整数である

N K

5 2

### 出力例 1

7

ありうる組は、(2,3),(5,3),(2,4),(3,4),(2,5),(3,5),(4,5)7 組です。

10 0

100

31415 9265

### 出力例 3

287927211

Score : 400 points

### Problem Statement

Takahashi had a pair of two positive integers not exceeding N, (a,b), which he has forgotten. He remembers that the remainder of a divided by b was greater than or equal to K. Find the number of possible pairs that he may have had.

### Constraints

• 1 \leq N \leq 10^5
• 0 \leq K \leq N-1
• All input values are integers.

### Input

Input is given from Standard Input in the following format:

N K

### Output

Print the number of possible pairs that he may have had.

5 2

### Sample Output 1

7

There are seven possible pairs: (2,3),(5,3),(2,4),(3,4),(2,5),(3,5) and (4,5).

10 0

100

31415 9265

287927211