import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int m = sc.nextInt();
        int n = sc.nextInt();
        int[] arr = new int[n];
        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        Arrays.sort(arr);
        int[] dp = new int[m + 1];
        for (int i = 1; arr[0] * i <= m; i++) {
            dp[arr[0] * i] = i;
        }
        for (int i = 1; i < n; i++) {
            for (int j = 0; j + arr[i] <= m; j++) {
                if (j != 0 && dp[j] == 0) {
                    continue;
                }
                for (int k = 1; j + arr[i] * k <= m; k++) {
                    dp[j + arr[i] * k] = Math.max(dp[j + arr[i] * k], dp[j] + k);
                }
            }
        }
        long ans = 0;
        for (int i = 0; i <= m; i++) {
            ans = Math.max(ans, dp[i]);
        }
        boolean[] isNotPrime = new boolean[m + 1];
        for (int i = 2; i < m; i++) {
            if (!isNotPrime[i]) {
                ans += dp[m - i];
                for (int j = 2; i * j <= m; j++) {
                    isNotPrime[i * j] = true;
                }
            }
        }
        System.out.println(ans);
    }
}