#include <bits/stdc++.h>

using namespace std;

int dp[10001] = {};
bool is_prime[10001];
vector<int> prime;

void sieve(int n) {
    fill(is_prime, is_prime + n + 1, true);
    is_prime[0] = false;
    is_prime[1] = false;
    for (int i = 2; i <= n; i++) {
        if (is_prime[i]) {
            prime.emplace_back(i);
            for (int j = 2 * i; j <= n; j += i) {
                is_prime[j] = false;
            }
        }
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int m, n;
    cin >> m >> n;
    vector<int> c(n);
    for (int i = 0; i < n; i++) cin >> c[i];
    sieve(m);
    fill(dp, dp + m + 1, -1);
    dp[m] = 0;
    for (int i = 0; i < n; i++) {
        for (int j = m - c[i]; j >= 0; j--) {
             if (dp[j + c[i]] >= 0) dp[j] = max(dp[j], dp[j + c[i]] + 1);
        }
    }
    int ans = *max_element(dp, dp + m + 1);
    for (int i = 0; i < (int)prime.size(); i++) {
        if (dp[prime[i]] >= 0) ans += dp[prime[i]];
    }
    cout << ans << "\n";
    return 0;
}