Mashmokh and ACM
题目描述
Mashmokh's boss, Bimokh, didn't like Mashmokh. So he fired him. Mashmokh decided to go to university and participate in ACM instead of finding a new job. He wants to become a member of Bamokh's team. In order to join he was given some programming tasks and one week to solve them. Mashmokh is not a very experienced programmer. Actually he is not a programmer at all. So he wasn't able to solve them. That's why he asked you to help him with these tasks. One of these tasks is the following.
A sequence of l integers b1,b2,...,bl (1≤b1≤b2≤...≤bl≤n) is called good if each number divides (without a remainder) by the next number in the sequence. More formally 
for all i (1≤i≤l-1).
Given n and k find the number of good sequences of length k. As the answer can be rather large print it modulo 1000000007 (109+7).
The first line of input contains two space-separated integers n,k(1≤n,k≤2000).
Output a single integer − the number of good sequences of length k modulo 1000000007 (109+7).
3 2
5
6 4
39
2 1
2
In the first sample the good sequences are: [1,1],[2,2],[3,3],[1,2],[1,3].
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