#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)

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);
}