import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int m = sc.nextInt();
        int n = sc.nextInt();
        int[] counts = new int[m + 1];
        Arrays.fill(counts, -1);
        counts[0] = 0;
        for (int i = 0; i < n; i++) {
            int x = sc.nextInt();
            for (int j = 0; j + x <= m; j++) {
                if (counts[j] < 0) {
                    continue;
                }
                counts[j + x] = Math.max(counts[j + x], counts[j] + 1);
            }
        }
        long ans = 0;
        boolean[] isNotPrimes = new boolean[m + 1];
        for (int i = 2; i <= m; i++) {
            if (!isNotPrimes[i]) {
                if (counts[m - i] > 0) {
                    ans += counts[m - i];
                }
                for (int j = 2; j * i <= m; j++) {
                    isNotPrimes[j * i] = true;
                }
            }
        }
        Arrays.sort(counts);
        System.out.println(ans + counts[m]);
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}