#include <iostream>
#include <cstring>
using namespace std;

const int kMAX_M = 10010;
const int kMAX_N = 30;

int M, N;
int C[kMAX_N];
int can_adjust[kMAX_M];

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

void Solve() {
    memset(can_adjust, -1, sizeof(can_adjust));
    can_adjust[0] = 0;
    for (int i = 0; i < N; i++) {
        for (int price = 0; price <= M; price++) {
            if (price - C[i] >= 0 && can_adjust[price - C[i]] >= 0) {
                can_adjust[price] = max(can_adjust[price], can_adjust[price - C[i]] + 1);
            }
        }
    }
    int answer = 0, max_num = 0;
    for (int price = 0; price <= M; price++) {
        int remaining = M - price;
        if (IsPrime(remaining) && can_adjust[price] > 0) {
            answer += can_adjust[price];
        }
        max_num = max(max_num, can_adjust[price]);
    }
    answer += max_num;
    cout << answer << endl;
}

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

    for (int i = 0; i < N; i++) {
        cin >> C[i];
    }

    Solve();
    
    /*
    for (int i = 0; i <= 100; i++) {
        cout << i << " " << can_adjust[i] << endl;
    }
    */

    return 0;
}