#define _USE_MATH_DEFINES
#include <sstream> //string stream its useful!
#include<string>
#include<iostream>
#include<utility> //pair
#include <vector> // vector
#include <algorithm>    // swap,sort,binary_search
#include <functional>   // std::greater
#include <map> //map
#include<set> //set
#include<queue> //queue
#include<list> //list
#include<cmath>
#include<numeric>
#include<cassert>
#include <iomanip> //cout<<setprecision

typedef long long ll;
#define ARRAY_LENGTH(array) (sizeof(array) / sizeof(array[0]))

using namespace std;
void omajinai() {
    
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout<<setprecision(15);
    //freopen("txt.csv","r",stdin);
}


template<int T>
vector<int> makesosuarray(){
    vector<int> ve(T,1);
    int k = ceil(sqrt(T));
    for(int j = 2; j < k;j++){
        if(ve[j] == 0) continue;
        for(int l = j*2; l<=T;l+=j) ve[l] = 0;
    }
    ve[0] = 0; ve[1] = 0;
    return ve;
}

vector<int> sosu = makesosuarray<10000>();

           
int main(){
    
    omajinai();
    int m,n;
    cin>>m>>n;
    vector<int> c(n); for_each(c.begin(),c.end(),[](int &c){cin>>c;});
    vector<int> l(m+1,-1);
    l[m] = 0;
    for(int t: c){
        for(int i = m-t;i>=0;i--) if(l[i+t]!=-1)l[i] = max(l[i],l[i+t] + 1);
    }
    
    ll ans = 0;
    for(int i = 0 ; i<=m;i++) if(sosu[i] ==1) ans+=max(0,l[i]);
    ans += *max_element(l.begin(),l.end());
    cout<<ans<<endl;
}