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++: /*Problem sennobushige 16D8104015E 18.5.16*/
#include <iostream>
#define N 1000000

int main(){
  int n=1,max;
  int A[N]={0},k=0;


  for(int l=0;l<N;l++){
    int p=0,tmp;
    std::cin>>n;
    int a[n]={0};
    std::cin>>max;
    if(n==0)break;
    for(int i=0;i<n;i++){
      std::cin>>a[i];
    }
    for(int i=0;i<n-1;i++){
      for(int j=i+1;j<n;j++){
	tmp=a[i]+a[j];
	if(tmp>=A[k]&&tmp<=max){
	  A[k]=tmp;
	  p++; 
	}
      }
    }
    if(p==0) A[k]=0;

      k++;
    //if(p!=0) std::cout<<sum<<"\n";
    //else std::cout<<"NONE\n";
  }
  for(int i=0;i<k;i++){
    if(A[i]!=0){
      std::cout<<A[i]<<"\n";
    }else{
      std::cout<<"NONE\n";
    }
   
  }



}

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

typedef int_fast32_t int32;
typedef int_fast64_t int64;

const int32 inf = 1e9+7;
const int32 MOD = 1000000007;
const int64 llinf = 1e18;

#define YES(n) cout << ((n) ? "YES\n" : "NO\n"  )
#define Yes(n) cout << ((n) ? "Yes\n" : "No\n"  )
#define POSSIBLE(n) cout << ((n) ? "POSSIBLE\n" : "IMPOSSIBLE\n"  )
#define ANS(n) cout << (n) << "\n"
#define REP(i,n) for(int64 i=0;i<(n);++i)
#define FOR(i,a,b) for(int64 i=(a);i<(b);i++)
#define FORR(i,a,b) for(int64 i=(a);i>=(b);i--)
#define all(obj) (obj).begin(),(obj).end()
#define rall(obj) (obj).rbegin(),(obj).rend()
#define fi first
#define se second
#define pb(a) push_back(a)
typedef pair<int32,int32> pii;
typedef pair<int64,int64> pll;

template<class T> inline bool chmax(T& a, T b) {
  if (a < b) { a = b; return true; } return false;
}
template<class T> inline bool chmin(T& a, T b) {
  if (a > b) { a = b; return true; } return false;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    while(1){
        int n,m;cin>>n>>m;
        if(n==0&&m==0)break;
        vector<int>a(n);
        for(int i=0;i<n;i++){
            cin>>a[i];
        }
        int ma=0;
        for(int i=0;i<n;i++){
                for(int j=i+1;j<n;j++){
                if(a[i]+a[j]<=m)ma=max(a[i]+a[j],ma);
            }
        }
        if(ma==0)cout<<"NONE"<<endl;
        else cout<<ma<<endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vb = vector<bool>;
using vs = vector<string>;
using msi = map<string, int>;
using mii = map<int, int>;
using psi = pair<string, int>;
using pii = pair<int, int>;
using tii = tuple<int, int>;
using vlai = valarray<int>;
#define rep(i,n) for(int i=0;i<n;i++)
#define range(i,s,n) for(int i=s;i<n;i++)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define fs first
#define sc second
#define INF 1E9
#define LINF 1E18*5
#define EPS 1E-9
#define MOD 1000000007
#define PI 3.1415926535897932384

template<class S, class T>ostream& operator<<(ostream&os, pair<S, T>p) { os << "[" << p.first << ", " << p.second << "]"; return os; };
template<class S>auto&operator<<(ostream&os, vector<S>t) { bool a = 1; for (auto s : t) { os << (a ? "" : " ") << s; a = 0; } return os; }

//int dx[]={1,1,1,0,-1,-1,-1,0},dy[8]={1,0,-1,-1,-1,0,1,1,1};
//
constexpr ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }

class compare {
public:
	bool operator()(tuple<int, int> a, tuple<int, int> b) {
		return (get<1>(a) < get<1>(b));
	}
};

int n, m;

void solve() {
	vl v(n);
	ll mx = -1;
	rep(i, n) {
		cin >> v[i];
	}
	sort(all(v));
	rep(i, n) {
		range(j, i+1, n) {
			if (v[i] + v[j] <= m)mx = max(v[i] + v[j], mx);
		}
	}
	cout<<(mx != -1 ? to_string(mx) : "NONE" ) << endl;
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	while (cin >> n >> m,n) {
		solve();
	}
}

C++: #include<bits/stdc++.h>

// Shrotening
#define fst first
#define snd second
#define pb push_back
#define mp std::make_pair

// Loop
#define FOR(i,a,b) for(auto i=(a);i<(b);++i)
#define RFOR(i,a,b) for(auto i=(a);i>=(b);--i)

#define REP(i,a) for(long i=0;i<(a);++i)
#define RREP(i,a) for(long i=(a);i>=0;--i)

#define EACH(i,a) for(auto (i)=(a).begin(),_END=(a).end();i!=_END;++i)
#define REACH(i,a) for(auto (i)=(a).rbegin(),_END=(a).rend();i!=_END;++i)

//Algorithm
#define ALL(a) (a).begin(), a.end()
#define RALL(a) (a).rbegin(), a.rend()
#define EXIST(a,x) ((a).find(x)!=(a).end())
#define SORT(a) std::sort((a).begin(), (a).end())
#define UNIQUE(a) std::sort((a).begin(), a.end()), a.erase(std::unique((a).begin(), a.end()), a.end());
#define SUM(a) std::accumulate((a).begin(), (a).end(), 0);

//Setting
#define OPT std::cin.tie(0);std::ios::sync_with_stdio(false);

//debug message
bool debug = true;
#define MSG(s)   if(debug){std::cout << s << std::endl;}
#define DEBUG(x) if(debug){std::cout << "debug(" << #x << "): " << x << std::endl;}

//alias
typedef long long LL;
typedef std::pair<int,int> PII;

typedef std::vector<char> VC;
typedef std::vector<int>  VI;
typedef std::vector<long> VL;
typedef std::vector<long long> VLL;
typedef std::vector<PII> VPII;

typedef std::vector< VC > VC2;
typedef std::vector< VI > VI2;
typedef std::vector< VL > VL2;
typedef std::vector< VLL > VLL2;

int n, m;
VI a(1000);
int main() {
    while(std::cin >> n >> m) {
        if(n == 0 && m == 0) break;
        REP(i, n) {
            std::cin >> a[i];
        }

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