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

入力

N K


入力例 1

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。

入力例 2

10 0


出力例 2

100


入力例 3

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.

Sample Input 1

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).

Sample Input 2

10 0


Sample Output 2

100


Sample Input 3

31415 9265


Sample Output 3

287927211