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])
		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<string.h>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>
#include<cmath>
#include<utility>
#define ll long long int
#define ld long double
#define INF 1000000000
#define EPS 0.0000000001
#define rep(i,n) for(i=0;i<n;i++)
using namespace std;
typedef pair<int, int> P;

string str;

int main()
{
  bool prime[1000005]={};//true   
  int n,x,i,j,k;

  rep(i,1000005)
    prime[i]=true;
  for(i=2;i<1000005;i++){
    if(prime[i])
      for(j=2;i*j<1000005;j++)
	prime[i*j]=false;
  }

  while(1){
    int price[30]={};
    int cost[2000005]={};
    cin>>n>>x;
    if(n==0 && x==0)break;
    rep(i,n){
      cin>>price[i];
      cost[price[i]]++;
    }

    rep(i,x)
      if(cost[i])
	rep(j,n)
	  cost[i+price[j]]++;


    for(i=x;i>0;i--)
      if(cost[i]>0 && prime[i])break;

    if(i)
      cout<<i<<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[31][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)
		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(i, 31) dp[i][0] = (1<<20);
		rep(j, x+1) dp[0][j] = -1;

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

C++: #include <stdio.h>
#include <algorithm>
using namespace std;
int n, x, a[30]; bool dp[1000001], prime[1000001];
int main() {
	prime[0] = true;
	for(int i = 2; i <= 1000000; i++) prime[i] = true;
	for(int i = 2; i <= 1000; i++) {
		if(!prime[i]) continue;
		for(int j = i * i; j <= 1000000; j += i) prime[j] = false;
	}
	while(scanf("%d%d", &n, &x), n) {
		for(int i = 0; i < n; i++) scanf("%d", &a[i]); sort(a, a + n);
		for(int i = 0; i < x; i++) dp[i + 1] = false; dp[0] = true;
		for(int i = 1; i <= x; i++) {
			for(int j = 0; j < n && i >= a[j]; j++) {
				if(dp[i - a[j]]) {
					dp[i] = true; break;
				}
			}
		}
		for(int i = x; i >= 0; i--) {
			if(dp[i] && prime[i]) {
				printf(i ? "%d\n" : "NA\n", i); break;
			}
		}
	}
}

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[1000002]={0};
int main()
{
	scanf("%d %d",&n,&p);
	while(1){
		//memset(youso, 0, sizeof(youso));
		for(int i=0;i<p+1;i++){
			youso[i]=0;
		}
		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<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<map>
#include<cstring>
using namespace std;

#define rep(i,n) for(int i=0;i<n;i++)
#define REP(n) rep(i,n)
#define all(n) n.begin(),n.end()

const int MAXN = 1000 * 1000 + 10;

bool p[MAXN];
bool ok[MAXN];

int main()
{
    p[0] = p[1] = 1;
    REP(MAXN)if(!p[i])for(int j = i*2;j<MAXN;j+= i)p[j] = 1;

    int n, x;
    while(cin >> n >> x && n)
    {
        memset(ok, 0, sizeof(ok));
        vector<int> dish;
        int t = 0;

        REP(n) {cin >> t; dish.push_back(t); ok[t] = 1;}

        sort(all(dish));
        //REP(n) cout << "d" << i << " " << dish[i] << endl;

        rep(j,x+1)if(ok[j])REP(n)for(int k = j+dish[i];k<x+1;k+=dish[i])ok[k] = 1;

        int ans = 0;
        for(int i = x-1;i >= 0; i--)if((!p[i]) && ok[i]){ ans = i; break;}

        if(ans == 0) cout << "NA" << endl;
        else cout << ans << endl;
    }

    return 0;
}

C++: #include<cstdio>
bool dp[1000001];
bool isprime(int& x){
  if(x > 2 && x % 2 == 0) return true;
  for(int i = 3 ; i * i <= x ; i += 2 ) if( x % i == 0) return true;
  return x == 1;
}
int solve(int& i){
  while(true){
    if(dp[i] && !isprime(i)) return i;
    i--;
  }
}
int main(){
  int n,x,data,ans;
  dp[0] = true;
  while(scanf("%d %d",&n,&x) , n){
    for(int i = 1 ; i <= x ; i++ ) dp[i] = false;
    for(int i = 0 ; i < n ; i++ ){
      scanf("%d",&data);
      for(int i = data ; i <= x ; i++ ) if(dp[i-data]) dp[i] = true;
    }
    if(ans = solve(x)) printf("%d\n",ans);
    else printf("NA\n");
  }
}

C++: #include<iostream>
#include<algorithm>
#define rep(i,n) for(int i=0;i<n;i++)
#define MP 10000001
using namespace std;
bool p[MP]; int n,x,c[35],ans;
bool rec(int a,int s){
	int f=0;
	for(int i=s;i>=0;i--)if(i==n-1||c[i]!=c[i+1])if(a>=c[i]){
		if(a==c[i])return 1;
		else{
			f=rec(a-c[i],i);
			if(f) return 1;
		}
	}
	return 0;
}
int main(){
	for(int i=2;i*i<MP;i++)if(!p[i])for(int j=i+i;j<MP;j+=i)p[j]=1;
	p[0]=p[1]=1;
	while(cin>>n>>x,n){
		rep(i,n)cin>>c[i]; sort(c,c+n);
		for(ans=x;ans>=c[0];ans--)if(!p[ans]&&rec(ans,n-1))break;
		if(ans<c[0])cout<<"NA"<<endl;
		else cout<<ans<<endl;
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdlib>
using namespace std;

#define rep(i,a) for(int i = 0 ; i < a ; i ++)
#define loop(i,a,b) for(int i = a ; i < b ; i ++)

int dt[40];
bool prime[100000];
bool dp[1000000];

int main(void){
	int n, x,lm;
	rep(i,100000){
		prime[i]=true;
	}
	for(int i=2;i<100000;i++){
		for(int j=i*2;j<100000;j+=i){
			prime[j]=false;
		}
	}

	while(cin>>n>>lm,n||lm){
		bool find = false;
		rep(i,100000){
			dp[i]=false;
		}
		dp[0] = 1;
		int m = 0 ; 
		loop(i,0,n){
			cin>>dt[i];
			rep(j,lm){
				dp[j + dt[i]] |= dp[j];
			}
			
		}
		//rep(i,sizeof(okapon))if(okapon[i])cout<<i<<endl;
		for(int i = lm ; i >= 0 ; i --){
			if(i==2){cout<<"NA"<<endl;break;}
			if(dp[i] && prime[i]){cout<<i<<endl;break;}
		}
	}
}