#include"bits/stdc++.h"

//#include<bits/stdc++.h>
using namespace std;
#define print(x) cout<<x<<endl;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define REP(i,a) for(int i=0;i<a;i++)
typedef long long ll;
typedef pair<int, int> PI;
typedef pair<int, PI> V;
typedef vector<int> VE;
const ll mod = 100000000;
int M, N;
int C[20];
int dp[21][10001];
//-----------------------------------------------------------------
vector<bool> primes;
void make_primes(int n) {
    primes.resize(n + 1, true);
    primes[0] = primes[1] = false;
    rep(i, 2, sqrt(n)) {
        if (primes[i]) {
            for (int j = 0; i * (j + 2) < n; j++)
                primes[i * (j + 2)] = false;
        }
    }
}
//-----------------------------------------------------------------
int main() {
    make_primes(101010);

    scanf("%d %d", &M, &N);
    rep(i, 0, N) scanf("%d", &C[i]);

    rep(i, 0, N + 1) rep(j, 0, M + 1) dp[i][j] = -1;

    dp[0][M] = 0;
    rep(i, 0, N) rep(j, 0, M + 1) if (0 <= dp[i][j]) {
        rep(k, 0, j / C[i]+1)
            dp[i + 1][j - k * C[i]] = max(dp[i + 1][j - k * C[i]], dp[i][j] + k);
    }

    int ans = 0;
    int _max = 0;
    rep(j, 0, M + 1) if (0 <= dp[N][j]) {
        if (primes[j]) ans += dp[N][j];
        _max = max(_max, dp[N][j]);
    }
    ans += _max;
    printf("%d\n", ans);
}