#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <functional>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;

#define fst first
#define scd second
#define PB push_back
#define MP make_pair
#define rep(i,x) for(int i=0;i<(x);++i)
#define rep1(i,x) for(int i=1;i<=(x);++i)
#define rrep(i,x) for(int i=(x)-1;i>=0;--i)
#define rrep1(i,x) for(int i=(x);i>=1;--i)
#define FOR(i,a,x) for(int i=(a);i<(x);++i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()

#define omajinai ios::sync_with_stdio(false);cin.tie(0)

template<typename T>T& max(T&a,T&b){if(a>=b)return a;return b;}
template<typename T>T& min(T&a,T&b){if(a<b)return a;return b;}
template<typename T>bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<typename T>bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<typename T>T get(){T a;cin>>a;return a;}
template<typename T>T rev(T a){reverse(all(a));return a;}
template<typename T>istream&operator>>(istream&is,vector<T>&vec){rep(i,vec.size())is>>vec[i];return is;}
template<typename T>vector<T>&sort(vector<T>&a){sort(all(a));return a;}

const int inf = 1e9;
const ll linf = 3e18;
const double eps = 1e-9;

int M, N, C[20];
int dp[10001];

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

    return n >= 2;
}

signed main()
{
    cin >> M >> N;

    rep(i, N) {
        cin >> C[i];
    }

    memset(dp, -1, sizeof(dp));
    dp[0] = 0;

    rep(i, N) {
        for (int j = C[i]; j <= M; ++j) {
            if (~dp[j - C[i]]) {
                dp[j] = max(dp[j], dp[j - C[i]] + 1);
            }
        }
    }

    int ans = 0;

    for (int i = M; i >= 0; --i) {
        if (is_prime(i) && ~dp[M - i]) {
            ans += dp[M - i];
        }
    }

    ans += *max_element(dp, dp + 10001);

    cout << ans << endl;
}