#include<iostream>

#include<cstdio>

#define N 20

using namespace std;

int dp[N+1];

int main(){

int n, k;

cin >> n >> k;

dp[0] = 1;

for(int i=1;i<=n;i++){

for(int j=1;j<=k;j++){

if(i < j) break;

dp[i] += dp[i-j];

}

}

printf("%d",dp[n]);

return 0;

}