#include <iostream>

using namespace std;

bool flag[1000001];
int n, x, m, price[30];

bool sosuu(int k) {
	if (k == 2) return true;
	else if (k % 2 == 0) return false;
	for (int i = 3; i*i<=k; i += 2)
		if (k % i == 0) return false;
	return true;
}
void next(int p, int k) {
	if (flag[k]) return;
	flag[k] = true;
	if (k > x) return;
	if (k > m) if (sosuu(k)) m = k;
	if (p == n) return;
	for (int i = 0; k + price[p] * i <= x; ++i)
		next(p + 1, k + price[p] * i);
}

int main() {
	while (cin >> n >> x, n || x) {
		for (int i = 0; i < 1000001; ++i) flag[i] = false;
		for (int i = 0; i < n; ++i)
			cin >> price[i];
		m = 0;
		next(0, 0);
		if (m) cout << m << endl;
		else cout << "NA" << endl;
	}
}