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")
		}
	}
}

Python: """ Created by Jieyi on 9/6/16. """


def primes(n):
    if n == 2:
        return [2]
    elif n < 2:
        return []
    s = list(range(3, n + 1, 2))
    mroot = n ** 0.5
    half = (n + 1) / 2 - 1
    i = 0
    m = 3
    while m <= mroot:
        if s[i]:
            j = int((m * m - 3) / 2)
            s[j] = 0
            while j < half:
                if j >= len(s):
                    j += m
                    continue
                s[j] = 0
                j += m
        i += 1
        m = 2 * i + 3
    return [2] + [x for x in s if x]


prime = primes(1000000)


def mark_array(index, arr_list, price_list):
    for t in price_list:
        if index + t < len(arr_list):
            arr_list[index + t] = 1


def algorithm():
    while True:
        n, total = map(int, input().split())
        if n == 0 and total == 0:
            break

        price = []
        arr_list = [0 for _ in range(total + 1)]

        for i in range(n):
            price.append(int(input()))

        for i in range(len(arr_list)):
            for p in price:
                if arr_list[i] == 0 and i % p == 0:
                    arr_list[i] = 1
                    mark_array(i, arr_list, price)
                elif arr_list[i] == 1:
                    mark_array(i, arr_list, price)

        if all(arr_list):
            print('NA')
        else:
            for i in range(total, -1, -1):
                if arr_list[i] == 1:
                    if i in prime:
                        print(i)
                        break
                if i == 0:
                    print('NA')


def main():
    algorithm()


if __name__ == '__main__':
    main()

Python: from math import sqrt
prime = [1 for _ in xrange(10**6+1)]
prime[1] = 0
prime[0] = 0
for i in xrange(2, int(sqrt(10**6+1))+1):
    if prime[i] == 1:
        for j in xrange(i+i, 10**6+1, i):
            prime[j] = 0
while True:
    N, X = map(int, raw_input().split())
    if (N, X) == (0, 0): break
    price = [input() for _ in xrange(N)]
    dp = [0] * (X+1)
    dp[0] = 1
    for i in xrange(X+1):
        if dp[i] == 0: continue
        for p in price:
            if i + p <= X:
                dp[i+p] = 1
    for i in range(X, -1, -1):
        if dp[i] == 1 and prime[i] == 1:
            print(i)
            break
    else:
        print("NA")

Python: def sieve():
    p = [1] * 1000001
    p[0] = p[1] = 0
    
    for i in range(1000):
        if p[i]:
            for j in range(i * i, 1000001, i):
                p[j] = 0
    return p

def solve(p, menu, x):
    menu.sort()
    
    num = [0] * (x + 1)
    for i in range(0,len(num),menu[0]):
        num[i] = 1
    for mi in menu[1:]:
        for i in range(len(num) - mi):
            if num[i] and not num[i + mi]:
                num[i + mi] = 1
                
    for i in reversed(range(1, len(num))):
        if p[i] and num[i]:
            return i
    return 'NA'

import sys
f = sys.stdin

p = sieve()
while True:
    n, x = map(int, f.readline().split())
    if n == 0:
        break
    menu = [int(f.readline()) for _ in range(n)]
    print(solve(p, menu, x))

Python: from datetime import datetime

def measure(f):
    measure_start = datetime.now()
    v = f()
    print(datetime.now() - measure_start)
    return v

input = raw_input
    
def init():
    table = [True] * 1000001
    table[0] = False
    table[1] = False
    n = len(table)

    def prime(p):
        for i in range(p + p, n, p):
            table[i] = False
    prime(2)
    prime(3)
    prime(5)
    prime(7)
    prime(11)
    prime(13)
    
    for i in range(2, n):
        if (i % 2 != 0 and i % 3 != 0 and i % 5 != 0 and
            i % 7 != 0 and i % 11 != 0 and i % 13 != 0):
            for j in range(i + i, n, i):
                table[j] = False
    return table
    
def solve(price, ps, is_prime):
    dp = [False] * (price + 1)

    if ps[0] <= price:
        dp[ps[0]] = True
    dp[0]     = True

    for i in range(1, len(ps)):
        cur_p = ps[i]
        for p in range(cur_p, price + 1):
            dp[p] = dp[p] or dp[p - cur_p]

    p = -1
    for i in range(0, price + 1):
        if is_prime[i] and dp[i]:
            p = i
    if p == -1:
        print("NA")
    else:
        print(p)
    
def main():
    table = measure(lambda : init())
    while True:
        n, price = map(int,input().split())
        if n == 0 and price == 0:
            return
        ps = []
        for i in range(n):
            ps.append(int(input()))
        solve(price, ps, table)

main()

Python: def main():
  tf = [True] * 1000001
  tf[0] = tf[1] = False
  for i in range(2, 1001):
    if tf[i]:
      for j in range(i ** 2 , 1000001, i):
        tf[j] = False
  primes = [i for i in range(1000001) if tf[i]]
  
  while True:
    n, x = map(int, input().split())
    if n == 0:
      break
    can = [False] * (x + 1)
    can[0] = True
    for _ in range(n):
      v = int(input())
      for i in range(x - v + 1):
        if can[i]: can[i + v] = True
    can_nums = [i for i in range(x, -1, -1) if can[i]]
    for num in can_nums:
      if num in primes:
        print(num)
        break
    else:
      print("NA")
   
main()

Python: input = raw_input

def init():
    table = [True] * 1000001
    table[0] = False
    table[1] = False
    n = len(table)
    for i in range(2, n):
        for j in range(i + i, n, i):
            table[j] = False
    return table
    
def solve(price, ps, is_prime):
    dp = []
    for i in range(len(ps)):
        dp.append([False] * (price + 1))

    if ps[0] <= price:
        dp[0][ps[0]] = True
    dp[0][0]     = True

    for i in range(1, len(ps)):
        for p in range(price + 1):
            if p >= ps[i]:
                dp[i][p] = dp[i - 1][p] or dp[i][p - ps[i]]
            else:
                dp[i][p] = dp[i - 1][p]

    p = -1
    for i in range(0, price + 1):
        if is_prime[i] and dp[len(ps) - 1][i]:
            p = i
    if p == -1:
        print("NA")
    else:
        print(p)
    
def main():
    table = init()
    while True:
        n, price = map(int,input().split())
        if n == 0 and price == 0:
            return
        ps = []
        for i in range(n):
            ps.append(int(input()))
        solve(price, ps, table)

main()