#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <math.h>
#include <set>
#include <map>
#include <queue>
#include <deque>
#include <stack>


#define f first
#define s second

using namespace std;

long long a[100];

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);

	int n, k;
	cin >> n >>  k;

	a[1] = 1;

	for (int i = 1; i <= n; i++)
		for (int j = i - 1; j >= max(0, i - k); j--)
			a[i] += a[j];

	//for (int i = 2; i <= n; i++)
//		cout << a[i] << " ";

//	cout << endl;

	cout << a[n];
}