#include <bits/stdc++.h>

#define LL long long
#define VI vector<int>
#define VVI vector<vector<int>>
#define VVVI vector<vector<vector<int>>>
#define VL vector<LL>
#define VVL vector<vector<LL>>
#define VVVL vector<vector<vector<LL>>>
#define VB vector<bool>
#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT(n) (1LL<<(n))
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());
#define EPS 1e-14

template<class T> T ceil(T a, T b) { return (a + b - 1) / b; }
template<class T> void print(T x) { std::cout << x << std::endl; }

const std::string YES = "YES", Yes = "Yes", NO = "NO", No = "No";
const std::vector<int> dy = { 0, -1, 0, 1 }, dx = { 1, 0, -1, 0 };    // 4近傍（右, 下, 左, 上）

using namespace std;

// nまでの素数のリストを作成(nを含む) O(N log log N)
vector<int> make_prime_list(int n) {
    vector<bool> is_prime(n + 1, true);
    is_prime[0] = false;
    is_prime[1] = false;

    vector<int> prime_list;
    for (int i = 2; i < n + 1; ++i) {
        if (!is_prime[i]) { continue; }
        prime_list.emplace_back(i);

        for (int j = i + i; j < n + 1; j += i) {
            is_prime[j] = false;
        }
    }
    return prime_list;  // 素数のリスト
    //return is_prime;  // すべての数値について素数かどうか
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    while (true) {
        int n, x;
        cin >> n >> x;
        if (n == 0 and x == 0) { break; }

        VI v(n);
        FOR(i, 0, n) {
            cin >> v[i];
        }


        vector<bool> dp(x + 1, false);
        dp[0] = true;

        FOR(i, 0, dp.size()) {
            FOE(x, v) {
                if (dp[i] and i + x < dp.size()) {
                    dp[i + x] = true;
                }
            }
        }

        auto prime_list = make_prime_list(x + 1);
        int ans = 0;
        FOE(p, prime_list) {
            if (p < x and dp[p]) {
                ans = max(ans, p);
            }
        }
        if (ans == 0) {
            print("NA");
        }
        else {
            print(ans);
        }
    }
}

