import java.io.*;
import java.util.Scanner;

public class Main {

    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int k = in.nextInt();

        long[] fib = new long[10005];
        long MOD = (long) 1e6 + 7;
        fib[0] = 1;
        fib[1] = 1;
        for (int i = 2; i < n; i++) {
            for (int j = Math.max(0, i - k); j < i; j++) {
                fib[i] = (fib[i] + fib[j]) % MOD;
            }
        }

        System.out.print(fib[n - 1]);


        in.close();
    }


}