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 <stdio.h>

int n,m[30];
bool prime[1000000];
bool c[1000000];

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;
		}
		//
	}
	for(;;);
	
	return 0;
}

C++: #include<stdio.h>
#include <string.h>
int isPrime(int x){
	int i;
	if(x<2) return 0;
	else if(x==2) return 1;
	if(x%2==0) return 0;
	for(i=3;i*i<=x;i+=2){
		if(x%i==0) return 0;
	}
	return 1;
}
int p,cnt,cnt2,food;
int n,d=0,g,kakaku[31],flag,youso[1000001]={0};
int main()
{
	scanf("%d %d",&n,&p);
	while(1){
		memset(kakaku, 0, sizeof(kakaku));
		memset(youso, 0, sizeof(youso));
		if(n==0&&p==0){
			break;
		}
		for(cnt=1;cnt<=n;cnt++){
			scanf("%d",&food);
			youso[food]=1;
			kakaku[cnt]=food;
		}
		for(cnt=0;cnt<=p;cnt++){
			if(youso[cnt]==1){
				for(cnt2=1;cnt2<=n;cnt2++){
					if(cnt+kakaku[cnt2]<=p){
						youso[cnt+kakaku[cnt2]]=1;
					}
				}
			}
		}
		flag=0;
		for(cnt=p;cnt>=0;cnt--){
			if(youso[cnt]==1){
				g=cnt;
				d=isPrime(g);
				if(d==1){
					flag=1;
					d=cnt;
					printf("%d\n",d);
					break;
				}
			}
		}
		if(flag==0){
			printf("NA\n");
		}
		d=0;
		flag=0;
		
		scanf("%d %d",&n,&p);
	}
	return 0;
}

C++: #include<stdio.h>
int isPrime(int x){
	int i;
	if(x<2) return 0;
	else if(x==2) return 1;
	if(x%2==0) return 0;
	for(i=3;i*i<=x;i+=2){
		if(x%i==0) return 0;
	}
	return 1;
}
int p,cnt,cnt2,food;
int n,d=0,g,kakaku[31],flag,youso[1000001]={0};
int main()
{
	scanf("%d %d",&n,&p);
	while(1){
		if(n==0&&p==0){
			break;
		}
		for(cnt=1;cnt<=n;cnt++){
			scanf("%d",&food);
			youso[food]=1;
			kakaku[cnt]=food;
		}
		for(cnt=0;cnt<=p;cnt++){
			if(youso[cnt]==1){
				for(cnt2=1;cnt2<=n;cnt2++){
					if(cnt+kakaku[cnt2]<=p){
						youso[cnt+kakaku[cnt2]]=1;
					}
				}
			}
		}
		flag=0;
		for(cnt=p;cnt>=0;cnt--){
			if(youso[cnt]==1){
				g=cnt;
				d=isPrime(g);
				if(d==1){
					flag=1;
					d=cnt;
					printf("%d\n",d);
					break;
				}
			}
		}
		if(flag==0){
			printf("NA\n");
		}
		d=0;
		flag=0;
		for(cnt=0;cnt<=p;cnt++){
			youso[cnt]=0;
		}
		scanf("%d %d",&n,&p);
	}
	return 0;
}

C++: #include <stdio.h>

int n,m[30];
/*
bool prime[1000000];
*/
bool c[1000000];

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 check(int prime){
	int flg=0,i;
	if(prime%2==0)return 0;
	for(i=3;i<prime;i+=2){
		if(prime%i==0){
			flg=1;
		}
	}
	if(flg==1)return 0;
	return 1;
}

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(;;);
		//
		for(i=0;i<x;i++){
			
			if(c[i]==1 && check(x-i)){
				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 FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pll> pip;
const ll INF = 1ll<<29;
const ll MOD = 1000000007;
const double EPS  = 1e-9;

vector<int> sieve(int n) {
	vector<int> res;
	vector<bool> is_prime(n + 1, true);
	
	is_prime[0] = is_prime[1] = false;
	
	for (int i = 2; i * i <= n; i++) if (is_prime[i]) {
		res.push_back(i);
		is_prime[i] = false;
		for (int j = 2; i * j <= n; j++) if (is_prime[i * j]) {
			is_prime[i * j] = false;
		}
	}
	
	REP(i, n + 1) if (is_prime[i]) res.push_back(i);
	sort(res.begin(), res.end());
	return res;
}

int n, x;
int v[30];

int main() {
	vector<int> prime = sieve(1000000);
	
	while (cin >> n >> x, n || x) {
		REP(i, n) scanf("%d", v + i);
		
		bitset<1000001> bs(1);
		REP(i, x + 1) if (bs[i]) {
			REP(j, n) if (i + v[j] <= x) bs[i + v[j]] = 1;
		}
		
		int ans = -1;
		int p = upper_bound(ALL(prime), x) - prime.begin() - 1;
		
		while (p >= 0) {
			if (bs[prime[p]]) {
				ans = prime[p];
				break;
			}
			p--;
		}
		
		if (ans == -1) puts("NA");
		else cout << ans << endl;
	}
	return 0;
}

C++: #include <stdio.h>
#include <string.h>

#define MAX_P 1000001

char isprime[MAX_P];

int n, e, m[30];
char dp[2000002];

int max(int a, int b){
    return a > b ? a : b;
}

void sieve(void){
    int x, y;
    memset(isprime, 1, sizeof(isprime));
    isprime[0] = isprime[1] = 0;
    for(x = 2; x * x <= MAX_P; x++){
        if(isprime[x]){
           for(y = x * x; y < MAX_P; y += x){
               isprime[y] = 0;
           }
        }
    }
}

int main(void){
    int x, y;
    sieve();
    while(1){
        scanf("%d%d", &n, &e);
        if(n+e == 0) break;
        for(x = 0; x < n; x++){
            scanf("%d", m+x);
        }
        memset(dp, 0, sizeof(dp));
        dp[0] = 1;
        for(x = 0; x < e; x++){
            if(!dp[x]) continue;
            for(y = 0; y < n; y++){
                dp[x + m[y]] = 1;
            }
        }
        for(x = e; x >= 2; x--){
            if(dp[x] && isprime[x]){
                printf("%d\n", x);
                break;
            }
        }
        if(x < 2){
            printf("NA\n");
        }
    }
    return 0;
}

C++: #include<stdio.h>
int a,b,c[1000001],d[31],e[1000001],i,j,m;
int main(void)
{
	scanf("%d %d",&a,&b);
	while(a!=0 && b!=0){
		m=0;
		for(i=0;i<a;i++){
			scanf("%d",&d[i]);
		}
		for(i=0;i<=b;i++){
			c[i]=0;
			e[i]=1;
		}
		c[0]=1;
		for(i=0;i<a;i++){
			for(j=0;j<=b;j++){
				if(c[j]==1 && j+d[i]<=b){
					c[j+d[i]]=1;
				}
			}
		}
		for(i=2;i*i<=b;i++){
			if(e[i]==1){
				for(j=i;j<=b;j=j+i){
					e[j]=0;
				}
			}
		}
		for(i=2;i<=b;i++){
			if(m<i && c[i]==1 && e[i]==1){
				m=i;
			}
		}
		if(m==0){
			printf("NA\n");
		}
		else{
			printf("%d\n",m);
		}
		scanf("%d %d",&a,&b);
	}
	return 0;
}