DP with forbidden

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();
        int l = in.nextInt();
        boolean[] frog = new boolean[n];
        for (int i = 0; i < l; i++) {
            frog[in.nextInt() - 1] = true;
        }
        int[] Arr = new int[100000];
        Arr[0] = 1;
        if (!frog[1])
            Arr[1] = 1;
        for (int i = 2; i < n; i++) {
            if (!frog[i]) {
                for (int j = Math.max(0, i - k); j < i; j++) {
                    Arr[i] += Arr[j];
                }
            }
        }
        System.out.println(Arr[n - 1]);
    }

}