#include"bits/stdc++.h"

//#include<bits/stdc++.h>
using namespace std;
#define print(x) cout<<x<<endl;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define REP(i,a) for(int i=0;i<a;i++)
typedef long long ll;
typedef pair<int, int> PI;
typedef pair<int, PI> V;
typedef vector<int> VE;
const ll mod = 100000000;

int m, n;
int c[10002];
int prime[10002];
int dp[21][10002];

void get_prime() {//1の時素数、0の時素数ではない
	rep(i, 1, 10001)prime[i] = 1;
	
	prime[1] = prime[0] = 0;
	prime[2] = 1;
	rep(i, 2, 10001) {
		if (prime[i] == 1) {
			for (int j = i + i; j < 10001; j += i) {
				prime[j] = 0;
			}
		}
	}
	return;
}

int main() {
	cin >> m;
	cin >> n;
	get_prime();
	REP(i,n)cin>>c[i];
	REP(i, n+1)REP(j,m+1)dp[i][j] = -1;
	dp[0][m] = 0;
	REP(i, n)REP(j, m + 1) {
		if (dp[i][j] >= 0) {
			REP(k, j / c[i] + 1)
				dp[i + 1][j - k*c[i]] = max(dp[i + 1][j - k*c[i]], dp[i][j] + k);
		}
	}

	int ans = 0;
	int _max = 0;
	REP(j, m + 1)if (dp[n][j] >= 0) {
		if (prime[j])ans += dp[n][j];
		_max = max(_max, dp[n][j]);
	}
	ans += _max; 
	print(ans);
}