#include <bits/stdc++.h>

#ifndef INCLUDE_BOOL_ARRAY_HPP
#define INCLUDE_BOOL_ARRAY_HPP

#include <cstring>
#include <limits>
#include <cassert>

namespace orliv {
template<unsigned int CAP>
struct BoolArray {
  typedef int memory_t;
  memory_t K;
  memory_t data[CAP];
  BoolArray() { clear_deep(); }
  void clear_deep(){ std::memset(data, sizeof(data), 0); K = 1; }
  void clear(){ K++; }
  bool within_k(int x, int k){ return data[x] + k >= K; }
  inline bool get(int x){ return data[x] == K; }
  inline void set(int x){ data[x] = K; }
};
}

#endif

using namespace std;

typedef long long ll;
typedef long double ld;
typedef tuple<int, int> duo;
const int dx[] = {0, 0, 1, -1, 1, 1, -1, -1};
const int dy[] = {1, -1, 0, 0, 1, -1, 1, -1};
const int Mod = 1000000000 + 0;
//{{{ templates
#define TT_ template<typename T>inline
#define TTF_ template<typename T,typename F>inline
TT_ T sq(T x){return x*x;}
TT_ T In(){T x;cin>>x;return x;}
TT_ void Out(T&x){cout<<x;}
TT_ void sort(T&v){sort(begin(v),end(v));}
TT_ void revs(T&v){reverse(begin(v),end(v));}
TT_ void uniq(T&v){sort(v);v.erase(unique(begin(v),end(v)),end(v));}
TT_ int ubnd(T&v,typename T::value_type x){return upper_bound(begin(v),end(v),x)-begin(v);}
TT_ int lbnd(T&v,typename T::value_type x){return lower_bound(begin(v),end(v),x)-begin(v);}
TTF_ void inpt(T&v,int n,F f){for(v.reserve(n);n--;v.emplace_back(f()));}
TTF_ void show(T&v,F f,string d=" ",string e="\n"){int i=0;for(auto&x:v)i++&&(cout<<d),f(x);cout<<e;}
TT_ typename T::iterator minel(T&v){return min_element(begin(v),end(v));}
TT_ typename T::iterator maxel(T&v){return max_element(begin(v),end(v));}

inline void fast_io(){ios_base::sync_with_stdio(0);cin.tie(0);}
inline int in(){int x;scanf("%d",&x);return x;}
inline ll pow_mod(ll a,ll k,ll m){ll r=1;for(;k>0;a=a*a%m,k>>=1)if(k&1)r=r*a%m;return r;}
inline ll mod_inv(ll a,ll p){return pow_mod(a,p-2,p);}
//}}} priority_queue queue deque front stringstream max_element min_element insert count make_tuple

const int MAX_N = 10100100;
orliv::BoolArray<MAX_N> dp;
bool sieve[MAX_N];

int main()
{
  for (int i = 2; i * i <= MAX_N; i++){
    if (sieve[i]) continue;
    for (int j = i * i; j <= MAX_N; j += i){
      sieve[j] = true;
    }
  }

  int n, x;
  while (n = in(), x = in(), n){
    dp.set(0);
    for (int i = 0; i < n; i++){
      int cost = in();
      for (int j = 0; j + cost <= x; j++){
        if (dp.get(j)) dp.set(j + cost);
      }
    }
    for (int i = x; i > 0; i--){
      if (sieve[i] && dp.get(i)){
        printf("%d\n", i);
        goto END;
      }
    }
    puts("NA");
END:;
    dp.clear();
  }
  return 0;
}