1 #include <cstdio>
 2 #include <cstring>
 3 #include <algorithm>
 4 #include <queue>
 5 #define inc(i,j,k) for(int i=j;i<=k;i++)
 6 #define maxn 1010
 7 #define ll long long
 8 using namespace std;
 9 
10 inline int read(){
11     char ch=getchar(); int f=1,x=0;
12     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1; ch=getchar();}
13     while(ch>=‘0‘&&ch<=‘9‘)x=x*10+ch-‘0‘,ch=getchar();
14     return f*x;
15 }
16 struct bigint{
17     int len,num[100];
18     void operator = (int a){len=0; memset(num,0,sizeof(num)); while(a)num[++len]=a%10,a/=10;}
19     void operator = (bigint a){
20         memset(num,0,sizeof(num)); inc(i,1,a.len)num[i]=a.num[i]; len=a.len;
21     }
22     void operator += (bigint a){
23         len=max(len,a.len);
24         inc(i,1,len){num[i]+=a.num[i]; if(num[i]>=10)num[i+1]+=num[i]/10,num[i]%=10;}
25         if(num[len+1])len++;
26     }
27     void print(){for(int i=len;i>=1;i--)printf("%d",num[i]);}
28 };
29 int n,k,x,y; bigint f[2][maxn];
30 int main(){
31     n=read(); k=read(); x=0; y=1; f[x][0]=1;
32     inc(i,1,k){
33         inc(j,0,n)f[y][j]=f[x][j]; inc(j,i,n)f[y][j]+=f[y][j-i]; swap(x,y);
34     }
35     f[x][n].print(); return 0;
36 }