1 #include <bits/stdc++.h>
2 #define _for(i,a,b) for(int i = (a);i < b;i ++)
3 typedef long long ll;
4 using namespace std;
5 int rnt = 0;
6 int N,K;
7 inline ll read()
8 {
9 ll ans = 0;
10 char ch = getchar(), last = ' ';
11 while(!isdigit(ch)) last = ch, ch = getchar();
12 while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
13 if(last == '-') ans = -ans;
14 return ans;
15 }
16 inline void write(ll x)
17 {
18 if(x < 0) x = -x, putchar('-');
19 if(x >= 10) write(x / 10);
20 putchar(x % 10 + '0');
21 }
22
23 void dfs(int st,int le,int fi)
24 {
25 if(st==K && le>=fi)
26 {
27 rnt ++;
28 return ;
29 }
30
31 _for(i,fi,le-(K-st)+1)
32 dfs(st+1,le-i,i);
33 }
34 int main()
35 {
36 N = read();// sum
37 K = read();// div
38 dfs(1,N,1);
39 write(rnt);
40 return 0;
41 }
