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 p[] = new int[K];
        int k[][] = new int[K][n + 1];

        for(int e = 0; e < K; e++)p[e] = in.nextInt();
        for(int i = 1; i < K; i++) k[i][0] = 1;
        for(int j = 1; j < n + 1; j++) if(j % p[0] == 0)k[0][j] = 1;

        for(int i = 1; i < K; i++){
            for(int j = 1; j < n + 1; j++){
                if(j < p[i]) k[i][j] = k[i - 1][j];
                else k[i][j] = k[i - 1][j] + k[i][j - p[i]];
            }
        }
        System.out.print(k[K - 1][n]);
    }
}