You’d like to collect n bees into k jars. As the bees are small, you don’t notice the difference between them. So, the only difference is made when there are different numbers of bees in different jars.

How many different ways are there to collect n bees into k jars?

Input

The first line of the input contains two integers n and k (1 ≤ n, k ≤ 30).

Output

The program should print the different number of ways to collect the bees.