1 /**************************************************************
 2     Problem: 3398
 3     User: Tunix
 4     Language: C++
 5     Result: Accepted
 6     Time:16 ms
 7     Memory:1588 kb
 8 ****************************************************************/
 9  
10 //BZOJ 3398
11 #include<cstdio>
12 #define F(i,j,n) for(int i=j;i<=n;++i)
13 int getint(){
14     int v=0,sign=1; char ch=getchar();
15     while(ch<‘0‘||ch>‘9‘) {if (ch==‘-‘) sign=-1; ch=getchar();}
16     while(ch>=‘0‘&&ch<=‘9‘) {v=v*10+ch-‘0‘; ch=getchar();}
17     return v*=sign;
18 }
19 const int N=100086,P=5000011;
20 int f[N][2],n,K;
21 int main(){
22     n=getint(); K=getint();
23     f[1][0]=f[1][1]=1;
24     F(i,2,n){
25         if(i-K-1>0) f[i][1]=f[i-K-1][0]+f[i-K-1][1];
26         else f[i][1]=1;
27         f[i][0]=f[i-1][0]+f[i-1][1];
28         if(f[i][0]>=P) f[i][0]-=P;
29         if(f[i][1]>=P) f[i][1]-=P;
30     }
31     printf("%d\n",(f[n][0]+f[n][1])%P);
32     return 0;
33 }