/*
 * 2024 ^_^
 *ThinhNguyen97
 * 
 */

import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Set;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.Scanner;
import java.util.Stack;






public class Solve_problems 
{
    static int n;//so luong dong xu
    static int[] coins=new int[1001];//luu menh gia cac dong xu
    static long[] dp=new long[1000001];
    
    static long solve(int S)
    {
        dp[0]=1;//so tien la 0 tuc la co 1 cach lua chon
        
        for(int j=0;j<n;j++)//duyet het mang
            for(int i=coins[j];i<=S;i++)
            {
                dp[i]+=dp[i-coins[j]];
                //dp[i]%=1000000007;
            }
                
        
        return dp[S];
    }

    public static void main(String[] args) 
    {
        Scanner sc = new Scanner(System.in);
        ////////
        int S=sc.nextInt();//so tien can tao ra
        n=sc.nextInt();
        for(int i=0;i<n;i++)
            coins[i]=sc.nextInt();
        System.out.println(solve(S));
        
        // Close the Scanner instance
        sc.close();
    }
}