#include <iostream>
#include <algorithm>
#include <cstring>
#include <sstream>
#include <map>
#include <queue>
#include <set>
#include <vector>
#include <stack>
#include <cstdio>
#include <cmath>
#define mk make_pair
#define pb push_back
#define printf printf_s
#define scanf scanf_s
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> pos;
const ll MOD = 1000000007, N = 100001, dx[4] = { -1,1,0,0 }, dy[4] = { 0,0,-1,1 }, MIN = -72340172838, MAX = 72340172838;

ll mn(ll a, ll b) {
	if (a == -1)return b;
	if (b == -1)return a;
	return min(a, b);
}
ll gcd(ll v1, ll v2) {
	if (v1 == 0)return v2; if (v2 == 0)return v1; if (v2 > v1)return gcd(v2%v1, v1); return gcd(v1%v2, v2);
}

ll pw(ll v1, ll v2) {
	ll v3 = 1;
	while (v2 > 0) {
		if (v2 % 2)v3 = (v3*v1) % MOD;
		v1 = (v1*v1) % MOD;
		v2 /= 2;
	}
	return v3;
}

struct ab {
	ll a, b;
	bool operator<(const ab& right) const {
		return right.b*a - right.a*b < 0;
	}
};

ll m, dp[10001],c[20],n;
bool pm[10001];
int main() {
	cin >> m >> n;
	for (int i = 0; i < n; i++)cin >> c[i];
	for (int i = m; i >= 0; i--) {
		for (int j = 0; j < n; j++) {
			if (i != m && dp[i] == 0)continue;
			if (i - c[j] >= 0)
				dp[i-c[j]] = max(dp[i - c[j]], dp[i] + 1);
		}
	}
	memset(pm, true, sizeof(pm)); pm[0] = pm[1] = false;
	for (int i = 2; i <= m; i++) {
		if (!pm[i])continue;
		for (int j = i * 2; j <= m; j += i)pm[j] = false;
	}
	ll ans = 0;
	for (int i = 0; i <= m; i++)ans += (dp[i] * pm[i]);
	ll v = 0;
	for (int i = 0; i <= m; i++)v = max(dp[i], v);
	cout << ans + v << endl;
	return 0;
}