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 <bits/stdc++.h>
                                        #include<iostream>
                                        #include<cstdio>
                                        #include<vector>
                                        #include<queue>
                                        #include<map>
                                        #include<cstring>
                                        #include<string>
                                        #include <math.h>
                                        #include<algorithm>
                                    //    #include <boost/multiprecision/cpp_int.hpp>
                                        #include<functional>
                                #define int long long
                                        #define inf  1000000007
                                        #define pa pair<int,int>
                                        #define ll long long
                                        #define pal pair<double,pa>
                                        #define ppa pair<int,int>
                                        #define ppap pair<pa,pa>
                                        #define ssa pair<string,int>
                                        #define  mp make_pair
                                        #define  pb push_back
                                        #define EPS (1e-10)
                                        #define equals(a,b) (fabs((a)-(b))<EPS)
                                  #define VI vector<int>
                                        using namespace std;
                                        
                                  class pas{
                                    	public:
                                    	int x,y;
                                    	pas(int x=0,int y=0):x(x),y(y) {}
                                    	pas operator + (pas p) {return pas(x+p.x,y+p.y);}
                                    	pas operator - (pas p) {return pas(x-p.x,y-p.y);}
                                    	pas operator * (int a) {return pas(x*a,y*a);}
                                    	pas operator / (int a) {return pas(x/a,y/a);}
                                    //	double absv() {return sqrt(norm());}
                                    	int norm() {return x*x+y*y;}
                                    	bool operator < (const pas &p) const{
                                    		return x != p.x ? x<p.x: y<p.y;
                                    	}
                                    	bool operator == (const pas &p) const{
                                    		return x==p.x && y==p.y;
                                    	}
                                    };
int n,V,W,K,N,L,R;
vector<int>ve;

//int dp[2][10001]={0};
int a[1010] ;
int s;
           signed main(){
           int n,m;
           	while(cin>>n>>m){
           		if(n==0)return 0;
           		
           		for(int i=0;i<n;i++)cin>>a[i];
           		int ans=-1;
           		for(int i=0;i<n;i++)for(int j=i+1;j<n;j++){
           			if(a[i]+a[j]<=m)ans=max(ans,a[i]+a[j]);
           		
           		}
           		if(ans==-1) cout<<"NONE"<<endl;
           		else cout<<ans<<endl;
           		
           	}
           	
           	
           	
           	
           	
           }

C++: #include <iostream>
#include <bitset>
#include <fstream>
#include <string>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <vector>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <functional>
#include <cctype>
#include <list>
#include <limits>
#include <unordered_map>
#include <cassert>
//#include <boost/multiprecision/cpp_int.hpp>

const double EPS = (1e-10);


using namespace std;
using Int = long long;
//using namespace boost::multiprecision;

const Int MOD = 998244353;

Int mod_pow(Int x, Int n) {
    Int res = 1;
    while(n > 0) {
        if(n & 1) res = (res * x) % MOD; //ビット演算(最下位ビットが1のとき)
        x = (x * x) % MOD;
        n >>= 1; //右シフト(n = n >> 1)
    }
    return res;
}

//最大公約数
template<typename T>
T gcd(T a, T b) {
    return b != 0 ? gcd(b, a % b) : a;
}

//最小公倍数
template<typename T>
T lcm(T a, T b) {
    return a * b / gcd(a, b);
}

//入出力高速化(非同期化)
void fast_input() {
    cin.tie(0);
    ios::sync_with_stdio(false);
}

int solve(int N, int M) {
    int ans = 0;
    vector<int> a(N);
    for (int i = 0; i < N; i++) {
        cin >> a[i];
    }
    
    for (int i = 0; i < N; i++) {
        for (int j = i+1; j < N; j++) {
            if (a[i] + a[j] <= M) {
                ans = max(ans, a[i] + a[j]);
            }
        }
    }
    return ans;
}

int main(void) {
    int N, M;
    vector<int> ans;
    while (1) {
        cin >> N >> M;
        if (!N && !M) break;
        ans.push_back(solve(N, M));
    }
    
    for (auto i: ans) {
        if (i) {
            cout << i << endl;
        } else {
            cout << "NONE" << endl;
        }
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)


int main(){
  while(true){
    int n,m,ans=0;
    cin>>n>>m;
    if(n+m==0)break;
    vector<int>v(n);
    rep(i,n)cin>>v[i];
    rep(i,n){
      for(int j=i+1;j<n;j++){
        if(v[j]+v[i]>ans&&m>=v[j]+v[i])ans=v[j]+v[i];
      }
    }
    if(ans)cout<<ans<<endl;
    else cout<<"NONE"<<endl;
  }
}