import java.util.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int k = sc.nextInt();
        int n = sc.nextInt();
        int[] arr = new int[n];
        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        int max = n;
        int[] dp = new int[k + 1];
        dp[0] = 1;
        for (int i = 0; i < k; i++) {
            for (int j = 0; j < max; j++) {
                if (i + arr[j] > k) {
                    max = j;
                    break;
                }
                dp[i + arr[j]] += dp[i];
                dp[i + arr[j]] %= MOD;
            }
        }
        System.out.println(dp[k]);
    }
}