Go: package main

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

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		n, m := io.NextInt(), io.NextInt()
		if n == 0 {
			break
		}
		a := make([]int, n)
		for i := 0; i < n; i++ {
			a[i] = io.NextInt()
		}
		ans := 0
		for i := 0; i < n; i++ {
			for j := i + 1; j < n; j++ {
				if a[i]+a[j] <= m {
					ans = intMax(a[i]+a[j], ans)
				}
			}
		}
		if ans == 0 {
			io.Println("NONE")
		} else {
			io.Println(ans)
		}
	}
}

func intMax(a, b int) int {
	if a < b {
		return b
	}
	return a
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: /*#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cmath>
#include<map>
#include<cstdio>
#include<stack>
#include<queue>
#include<fstream>
#include<cstdio>
#include<deque>
#include<iomanip>
#include <random>

using namespace std;
#define ok1 printf("ok1\n");
#define ok2 printf("ok2\n");
#define M 1000000000000000000LL
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,s,n) for(int i=(s);i<(n);i++)
#define repr(i,n) for(int i=n-1;i>=0;i--)
#define REPR(i,s,n) for(int i=(s);i>=(n);(i)--)
#define all(a) (a).begin(),(a).end()
#define reall(a) (a).rbegin(),(a).rend()
#define pb push_back
#define pf push_front
#define MIN(a,b) a=min((a),(b))
#define MAX(a,b) a=max((a),(b))
#define SIZE(v) (int)v.size()
const double pi = acos(-1.0);

typedef vector<int> vi;
typedef vector<string> vs;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef deque<ll> dll;
#define mod 1e9 + 7;

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	cout.setf(ios::fixed);
	cout.precision(20);

	vs v;
	string s1, s2;
	vs cs1, cs2;
	while (true) {
		cin >> s1;
		if (s1 == ".") break;
		cin >> s2;
		ll sum = 0;
		if (s1 == s2) v.pb("IDENTICAL");
		else {
			rep(i, s1.size()) {
				rep(j, s1.size()) {
					if (i != j && s1[i] == '"' && s1[j] == '"') {
						cs1.pb(s1.substr(i + 1, j - 1));
						s1[i] = '0'; s1[j] = '0';
					}

				}
			}
			rep(i, s2.size()) {
				rep(j, s2.size()) {
					if (i != j && s2[i] == '"' && s2[j] == '"') {
						cs2.pb(s2.substr(i + 1, j - 1));
						s2[i] = '0'; s2[j] = '0';
					}

				}
			}
			rep(i, cs1.size()) {
				cout << cs1[i] << " " << cs2[i] << endl;
				if (cs1[i] != cs2[i]) sum++;
				if (sum == 2) break;
			}
			if (sum == 1) v.pb("CLOSE");
			else v.pb("DIFFERENT");
		}
	}
	rep(i, v.size()) cout << v[i] << endl;
	return 0;
}*/
#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cmath>
#include<map>
#include<cstdio>
#include<stack>
#include<queue>
#include<fstream>
#include<cstdio>
#include<deque>
#include<iomanip>

using namespace std;
#define ok1 printf("ok1\n");
#define ok2 printf("ok2\n");
#define M 1000000000000000000LL
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,s,n) for(int i=(s);i<(n);i++)
#define repr(i,n) for(int i=n-1;i>=0;i--)
#define REPR(i,s,n) for(int i=(s);i>=(n);(i)--)
#define all(a) (a).begin(),(a).end()
#define reall(a) (a).rbegin(),(a).rend()
#define pb push_back
#define pf push_front
#define MIN(a,b) a=min((a),(b))
#define MAX(a,b) a=max((a),(b))
#define SIZE(v) (int)v.size()
const double pi = acos(-1.0);

typedef vector<int> vi;
typedef vector<string> vs;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef deque<ll> dll;
#define mod 1e9 + 7;

int main()
{
	ios_base::sync_with_stdio(false);

	ll n, m;
	vll w;
	while (true) {
		cin >> n >> m;
		if (n == 0 && m == 0) break;
		vll v(n);
		ll ans = 0;
		rep(i, n) cin >> v[i];
		rep(i, n) {
			rep(j, n) {
				if (i == j) break;
				if (v[i] + v[j] == m) {
					ans = m;
				}
				else {
					if (ans < v[i] + v[j] && v[i] + v[j] < m)
						ans = v[i] + v[j];
				}
			}
		}
		w.pb(ans);
		
	}
	rep(i, w.size()) {
		if (w[i] == 0) puts("NONE");
		else cout << w[i] << endl;
	}
	return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
typedef long long ll;
#define INF (1<<30)
#define INFLL (1ll<<60)
typedef pair<int, int> P;
typedef pair<int, P> E;
#define MOD (1000000007ll)
#define l_ength size

void mul_mod(ll& a, ll b){
	a *= b;
	a %= MOD;
}

void add_mod(ll& a, ll b){
	b += MOD;
	a += b;
	a %= MOD;
}

int main(void){
	int n,i,l,r;
	ll m,a[1234],ans;
	bool flag;
	while(true){
		cin >> n >> m;
		if(!(n&&m)){
			break;
		}
		flag = false;
		r = (n-1);
		ans = 0ll;
		for(i=0; i<n; ++i){
			cin >> a[i];
		}
		sort(a,a+n);
		for(l=0; l<n; ++l){
			while(r && a[l]+a[r]>m){
				--r;
			}
			if(a[l]+a[r]<=m && l!=r){
				flag = true;
				ans = max(ans,a[l]+a[r]);
			}
		}
		if(flag){
			cout << ans << endl;
		}else{
			cout << "NONE" << endl;
		}
	}
	return 0;
}

C++: #include<iostream>
#include<vector>
using namespace std;
int main(){
  vector<int> a(1000);
  int n,m,b,max=0;
  while(n!=0 && m!=0){
    max=0;
    cin>>n>>m;
    for(int i=0;i<n;i++){
      cin>>b;
      a[i]=b;
    }
  
    for(int j=0;j<n;j++){
      for(int k=0;k<n;k++){
	if(j!=k){
	  if(max<a[j]+a[k] && a[j]+a[k]<=m){
	    max=a[j]+a[k];
	  }
	}
      }
    }
    if(max==0 && n!=0&&m!=0){
      cout<<"NONE"<<endl;
    }else if(n!=0&&m!=0){
      cout<<max<<endl;
    }
  }
}

C++: #include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <utility>
#include <string>
#include <stack>
#include <regex>

#define REP(i, n) for (int i = 0; i < n; i++)
#define ALL(v) (v).begin(), (v).end()
#define vi vector<int>
#define vvi vector<vector<int>>
#define vl vector<long long>
#define vvl vector<vector<long long>>

using namespace std;

typedef long long ll;

int main()
{
  int n;
  int m;
  while (1)
  {
    cin >> n >> m;
    if (n == 0)
      break;
    vi a(n);
    REP(i, n)
    {
      cin >> a[i];
    }
    int cnt;
    int ans = 0;
    REP(i, n)
    {

      REP(j, n)
      {
        if (i == j)
        {
          continue;
        }
        cnt = a[i] + a[j];
        if (cnt > m)
        {
          continue;
        }
        ans = max(ans, cnt);
      }
    }
    if (ans == 0)
    {
      cout << "NONE" << endl;
    }
    else
    {
      cout << ans << endl;
    }
  }
  return 0;
}