#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;
const ll INF=1e15;
const int MAX=10001;
vector<int> prime;
bool isprime[MAX];

void sieve(){
	for(ll i=3; i<MAX; i+=2){
		isprime[i]=1;
	}
	isprime[2]=1;
	prime.push_back(2);
	for(int i=3; i<MAX; i++){
		if(isprime[i]){
			prime.push_back(i);
			for(int j=2*i; j<MAX; j+=i){
				isprime[j]=0;
			}
		}
	}
	return;
}

int main()
{
	int m, n;
	cin>>m; cin>>n;
	int c[21];
	for(int i=1; i<=n; i++) cin>>c[i];
	ll dp[21][10001];
	for(int i=0; i<=n; i++){
		fill(dp[i], dp[i]+m+1, -INF);
		dp[i][0]=0;
	}
	for(int i=1; i<=n; i++){
		for(int j=0; j<=m; j++){
			dp[i][j]=dp[i-1][j];
			if(j>=c[i]) dp[i][j]=max(dp[i][j], dp[i][j-c[i]]+1ll);
		}
	}
	sieve();
	ll ans=0;
	for(int i=0; prime[i]<m; i++){
		if(dp[n][m-prime[i]]>=0) ans+=dp[n][m-prime[i]];
	}
	ll mx=0;
	for(int i=0; i<=m; i++){
		mx=max(mx, dp[n][i]);
	}
	ans+=mx;
	cout<<ans<<endl;
	return 0;
}