#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
//#include<cctype>
#include<climits>
#include<iostream>
#include<string>
#include<vector>
#include<map>
//#include<list>
#include<queue>
#include<deque>
#include<algorithm>
//#include<numeric>
#include<utility>
//#include<memory>
#include<functional>
#include<cassert>
#include<set>
#include<stack>
#include<random>

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, -1, 0, 1};
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int, int> pii;

const int MAXN = 22;
const int MAXM = 10100;
int C[MAXN];
int dp[MAXM];

bool isPrime(int n) {
    if (n <= 1) return false;
    for (int i = 2; i*i <= n; i++) {
        if (n%i == 0) return false;
    }
    return true;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int M, N;
    cin >> M;
    cin >> N;
    for (int i = 0; i < N; i++)
        cin >> C[i];
    memset(dp, -1, sizeof(dp));
    dp[M] = 0;
    for (int j = M; j >= 0; j--) if (dp[j] >= 0) {
        for (int i = 0; i < N; i++) {
            if (j >= C[i]) {
                dp[j-C[i]] = max(dp[j-C[i]], dp[j]+1);
            }
        }
    }
    int ans = *max_element(dp, dp+MAXM);
    for (int i = 0; i <= M; i++) if (dp[i] >= 0 && isPrime(i)) {
        ans += dp[i];
    }
    cout << ans << endl;
    return 0;
}