# include <bits/stdc++.h>
using namespace std;
typedef long long ll; 
# define int long long
# define lc u << 1
# define rc u << 1 | 1
# define fi first
# define se second
const int N = 10005;

int m, n;
int a[N];
bool com[N];
int pri[N], tot;
void sieve (int n)
{
    for (int i = 2; i <= n; i ++ )
    {
        if (!com[i]) pri[ ++ tot] = i;
        for (int j = 1; j <= tot && i * pri[j] <= n; j ++ )
        {
            com[i * pri[j]] = 1;
            if (i % pri[j] == 0) break;
        }
    }
}
int dp[N]; // i元最多可以买几个面包
signed main ()
{
    sieve (10000);
    scanf ("%lld%lld", &m, &n);
    for (int i = 1; i <= n; i ++ ) scanf ("%lld", &a[i]); 
    memset (dp, -0x3f3f3f3f, sizeof dp);
    dp[0] = 0;
	for (int i = 1; i <= n; i ++ )
    {
		for (int j = a[i]; j <= m; j ++ )
            dp[j] = max (dp[j], dp[j - a[i]] + 1);
	}
    int ans = 0;
    for (int i = 1; i <= tot; i ++ )
    {
        if (pri[i] > m) break;
        if (dp[m - pri[i]] > 0)
            ans += dp[m - pri[i]];
    }
    int mx = 0;
    for (int i = 1; i <= m; i ++ ) mx = max (mx, dp[i]);
    printf ("%lld\n", ans + mx);
	return 0;
}