// yukicoder: No.385 カップ麺生活
// 2019.7.14 bal4u

#include <stdio.h>
#include <string.h>

#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif

int in() {   // 非負整数の入力
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

#define MAX  10000
#define SQRT 100
char prime[MAX+3];

void sieve() {
	int i, j;
	
	memset(prime+2, 1, MAX);
	for (i = 4; i <= MAX; i+=2) prime[i] = 0;
	for (i = 3; i <= SQRT; i += 2) if (prime[i]) {
		for (j = i*i; j <= MAX; j += i) prime[j] = 0;
	}
}

int M, N;
int c[25];
int dp[MAX+5];

int main()
{
	int i, j, k, ans;

	sieve();
	M = in(), N = in();
	for (i = 0; i < N; i++) c[i] = in();
	memset(dp, -1, sizeof(dp));
	dp[M] = 0;
	for (i = 0; i < N; i++) {
		for (j = M; j; j--) if (dp[j] >= 0 && (k = j-c[i]) >= 0) {
			if (dp[k] == 0 || dp[k] < dp[j]+1) dp[k] = dp[j]+1;
		}
	}
	ans = 0;
	k = 0; for (i = 0; i < M; i++) if (dp[i] > 0) {
		if (dp[i] > k) k = dp[i];
		if (prime[i]) ans += dp[i];
	}
	printf("%d\n", ans+k);
	return 0;
}