#include "bits/stdc++.h"
#define REP(i,a,b) for(i=a;i<b;++i)
#define rep(i,n) REP(i,0,n)
using namespace std;

bool isprime(int n) {
	int i;
	if (n < 2) return false;
	for (i = 2; i*i <= n; i++) {
		if (n % i == 0) return false;
	}
	return true;
}

int M, N;
int c[20];
int dp[10005];
signed main(void)
{
	int i, j, k, l;
	cin >> M >> N;
	rep(i, N) cin >> c[i];
	for (i = M; i > 0; --i) {
		if (i != M && dp[i] == 0) continue;
		rep(j, N) {
			int next = i - c[j];
			if (next >= 0) {
				if (dp[next] < dp[i] + 1) {
					dp[next] = dp[i] + 1;
				}
			}
		}
	}
	int ans = 0;
	rep(i, M) {
		if (ans < dp[i]) ans = dp[i];
	}
	rep(i, M) {
		if (dp[i] && isprime(i)) ans += dp[i];
	}
	cout << ans << endl;
	return 0;
}