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-----
5 2

-----Sample Output-----
7

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

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