Description

Partition the integer $n$ into $k$ parts, where each part must be non-empty. Determine how many distinct partition methods exist. For example, when $n=7$ and $k=3$, the following three partition methods are considered the same: $1,1,5$; $1,5,1$; $5,1,1$.

Input Format

One line containing two integers, $n$ and $k$.

Output Format

One line with a single integer representing the number of distinct partition methods.

Sample 1

The four partition methods are: $1,1,5$; $1,2,4$; $1,3,3$; $2,2,3$.

7 3

4

Data Range and Hint

$6 \leq n \leq 200,$ $2 \leq k \leq 6$.