Go: package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
	)

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	for scanner.Scan() {
		buf := strings.Split(scanner.Text(), " ")
		n, _ := strconv.Atoi(buf[0])
		x, _ := strconv.Atoi(buf[1])
		if n == 0 && x == 0 {
			break
		}
		prime_table := make([]int, 1000001)
		prime_table[0] = -1
		prime_table[1] = -1
		for i := 2; i < 1000001; i++ {
			if prime_table[i] != -1 {
				prime_table[i] = 1
				for j := 2*i; j < 1000001; j += i {
					prime_table[j] = -1 // -1 means "not prime"
				}
			}
		}
		dp := make([]int, x+1)
		dp[0] = 1
		menu := make([]int, n)
		for i := 0; i < n; i++ {
			scanner.Scan()
			menu[i], _ = strconv.Atoi(scanner.Text())
		}
		for i := 0; i < n; i++ {
			for j := 0; j <= x; j++ {
				if menu[i] <= j && dp[j-menu[i]] != 0 {
					// log.Println(dp)
					dp[j] = 1
				}
			}
		}
		flag := true
		for j := x; j >= 0; j-- {
			if prime_table[j] == 1 && dp[j] == 1 {
				flag = false
				fmt.Println(j)
				break
			}
		}
		if flag {
			fmt.Println("NA")
		}
	}
}

C++: #include<iostream>
#include<algorithm>
using namespace std ;
long m ;
long long dp[ 1000000 + 1 ] ;
void ans( int cnt ,long long dp[] )
{
	int a = cnt + 1 ;
	LOOK :
	a-- ;
	while( dp[ a ] != 1 )
	{
		a-- ;
		if( a < 2 )
		{
			END :
			cout << "NA" << endl ;
			return ;
		}
	}
	if( a < 2 )
	{
		goto END ;
	}
	if( a % 2 == 0 )
	{
		goto LOOK ;
	}
	if( a == 2 )
	{
		cout << a << endl ;
		return ;
	}
	for( int i = 3 ; i * i <= a ; i += 2 )
	{
		if( a % i == 0 )
		{
			goto LOOK ;
		}
	}
	cout << a << endl ;
	return ;
}
int main()
{
	int n ;
	int dmon[ 30 ] ;
	int j ;
	while( cin >> n >> m )
	{
		if( n== 0 && m == 0 )
		{
			break ;
		}
		int cnt = m ;
		fill_n( dp ,1000001 ,0 ) ;
		for( int i = 0 ; i < n ; i++ )
		{
			cin >> dmon[ i ] ;
		}
		for( int i = 0 ; i + dmon[ 0 ] <= m ; )
		{
			for( j = 0 ; j < n && i + dmon[ j ] <= m ; j++ )
			{
				dp[ i + dmon[ j ] ] = 1 ;
			}
			i++ ;
			while( dp[ i ] != 1 )
			{
				i++ ;
			}
		}
		ans( cnt , dp ) ; 
	}
	return 0 ;
}

C++: #include <stdio.h>

int n,m[32];

bool prime[1000010];
bool c[1000010];

void saiki(int total){
	int i;
	if(total<=0){
		return;
	}
	
	for( i=0 ; i<n ; i++){
		total-=m[i];
		if(c[total]==1)continue;
		if(total>=0){
			c[total]=1;
		}
		saiki(total);
	}
}

int main(void)
{
	int i,j;
	//f
	prime[0]=1;
	prime[1]=1;
	for(i=3;i<1000000;i++){
		if(i%2==0){
			prime[i]=1;
		}
	}
	for(i=3;i<1000000;i++){
		if(prime[i]==0){
			for(j=(i+i);j<1000000;j+=i){
				prime[j]=1;
			}
		}
	}
	//
	while(1){
		int x;
		int flg=0;
		scanf("%d%d",&n,&x);
		if(n==0)break;
		
		for(i=0;i<n;i++){
			scanf("%d",&m[i]);
		}
		saiki(x);
		//
		for(i=0;i<x;i++){
			
			if(c[i]==1 && prime[x-i]==0){
				flg=1;
				break;
			}
		}
		if(flg==1){
			printf("%d\n",x-i);
		}
		else puts("NA");
		for(i=0;i<1000000;i++){
			c[i]=0;
		}
		//
	}
	
	
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define MAX_X (1000005)

void calcPrime(bitset < MAX_X > &prime)
{
    for ( int i = 2; i < MAX_X; i++ ) {
        prime[i] = true;
    }

    for ( int i = 2; i * i < MAX_X; i++ ) {
        if ( prime[i] ) {
            for ( int j = i * i; j < MAX_X; j += i ) {
                prime[j] = false;
            }
        }
    }
}

int main()
{
    int N, X;
    bitset < MAX_X > prime;

    calcPrime(prime);

    while ( cin >> N >> X, N || X ) {
        bool dp[MAX_X] = {};

        dp[0] = true;
        for ( int i = 0; i < N; i++ ) {
            int v;
            cin >> v;
            for ( int j = 0; j <= X; j++ ) {
                if ( dp[j] && j + v <= X ) {
                    dp[j + v] = true;
                }
            }
        }
        int k = X;
        while ( k > 0 && (!prime[k] || !dp[k]) ) {
            k--;
        }
        if ( k > 0 ) {
            cout << k << endl;
        } else {
            cout << "NA" << endl;
        }
    }

    return (0);
}

C++: #include<cstdio>
#include<cstring>
#include<algorithm>
#include<functional>
#include<vector>
#include<stack>
#include<queue>
#include<iostream>
using namespace std;
int dp[1000001],flg[1000001];
int main(void)
{
	for(int i=2;i<=1000000;i++) flg[i]=1;
	for(int i=2;i*i<=1000000;i++){
		if(flg[i]==1){
			for(int j=2;j*i<1000000;j++) flg[i*j]=0;
		}
	}
	int kin[30],n,x;
	while(1) {
		cin>>n>>x;
		if(n==0 && x==0) break;
		for(int i=0;i<n;i++) cin>>kin[i];
		for(int i=0;i<1000001;i++) dp[i]=0;
		dp[0]=1;
		for(int i=0;i<n;i++) {
			for(int j=0;j<=x;j++) if(dp[j]==1) dp[j+kin[i]]=1;
		}
		;
		int data,no=0;
		for(int i=x;i>1;i--) {
			if(flg[i]==1 && dp[i]==1){data=i;no=1;break;}
		}
		if(no==0) cout<<"NA"<<endl;
		else cout<<data<<endl;
	}
}

C++: #include <vector>
#include <iostream>
#include <utility>
#include <algorithm>
#include <string>
#include <deque>
#include <queue>
#include <tuple>
#include <queue>
#include <functional>
#include <cmath>
#include <iomanip>
#include <map>
#include <set>
#include <numeric>
#include <unordered_map>
#include <unordered_set>
#include <complex>
#include <iterator>
#include <array>
#include <memory>
#include <stack>
#define vi vector<int>
#define vvi vector<vector<int> >
#define ll long long int
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vb vector<bool>
#define vc vector<char>
#define vs vector<string>
#define ld long double
#define INF 1e9
#define EPS 0.0000000001
#define rep(i,n) for(int i=0;i<n;i++)
#define loop(i,s,n) for(int i=s;i<n;i++)
#define all(in) in.begin(), in.end()
template<class T, class S> void cmin(T &a, const S &b) { if (a > b)a = b; }
template<class T, class S> void cmax(T &a, const S &b) { if (a < b)a = b; }
#define MAX 1000000+1
using namespace std;
typedef pair<int, int> pii;
typedef pair<double,double>pdd;
typedef pair<ll,ll>pll;
vector<bool>Isprime(MAX+1,true);
int main(){
    int n;
    int Primecounter =0;                  //Primearray counter;
    for(int i = 2; i<MAX+1;i++){
        if(Isprime[i]){
            for(int j = 2;i*j<MAX;j++)
                Isprime[i*j] = false;//テァツエツ?ヲツ閉ーテ」ツ?ェテ」ツつ臼rimearrayテ」ツ?ォテヲツ?シテァツエツ催」ツ?療」ツ?ヲテ」ツ?敕」ツ?ョテ・ツ?催ヲツ閉ーテ」ツつ津・ツ?ィテ」ツ?ヲfalseテ」ツ?ォ
            Primecounter++;
        }
    }
    int x;
    while(cin>>n>>x,n+x){
        vvi dp(x+1,vi(30,0));
        vi tiya;
        rep(i,n){
            int gotiusa_is_a_god_anime;
            cin>>gotiusa_is_a_god_anime;
            tiya.push_back(gotiusa_is_a_god_anime);
            dp[gotiusa_is_a_god_anime][i]=1;
        }
        rep(i,x+1)rep(j,n){
            if(dp[i][j]){
                dp[i][j+1]=dp[i][j];
               if(i+tiya[j]<=x) dp[i+tiya[j]][j]=1;
            }
        }
        int maxi=-INF;
        for(int i=1; i<=x;i++)if(Isprime[i]&&dp[i][n])cmax(maxi,i);
        if(maxi!=-INF&&maxi!=1)cout<<maxi<<endl;
        else cout<<"NA"<<endl;
    }
}

C++: #include <cstdio>
#include <algorithm>
using namespace std;
#define REP(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) REP(i, 0, n)
#define M 1000001
bool p[M];
int dish[31];
int dp[M];
int n, x;
int main()
{
	rep(i, M) p[i] = true;
	p[0] = p[1] = false;
	for (int i = 2; i * i < M; ++i)
		if (p[i]) for (int j = 2 * i; j < M; j += i)
			if (p[j]) p[j] = false;

	while (true) {
		scanf("%d%d", &n, &x);
		if ((n | x) == 0) break;
		rep(i, n) scanf("%d", dish + i);
		
		rep(j, x+1) dp[j] = -1;
		dp[0] = (1<<20);

		int k = 1;
		rep(i, n) REP(j, 1, x+1) {
			if (dp[j] >= 0)
				dp[j] = (1<<20);
			else if (j < dish[i] || dp[j-dish[i]] <= 0)
				dp[j] = -1;
			else
				dp[j] = dp[j-dish[i]] - 1;
		}
		int res = 0;
		rep(j, x+1) if (p[j] && dp[j] >= 0) res = j;
		if (res > 0)
			printf("%d\n", res);
		else
			puts("NA");
	}
	return 0;
}