Go: ///
// File:  0529.go
// Author: ymiyamoto
//
// Created on Wed Feb 28 20:39:28 2018
//
package main

import (
	"fmt"
	"sort"
)

func max(n, m int) int {
	if n < m {
		return m
	} else {
		return n
	}
}

func main() {
	for {
		var N, M int
		fmt.Scan(&N, &M)
		if N == 0 && M == 0 {
			break
		}

		arr := make([]int, N+1)
		for i := 1; i <= N; i++ {
			fmt.Scan(&arr[i])
		}
		sort.Ints(arr)

		sums := make([]int, len(arr)*len(arr))
		for i := 0; i < len(arr); i++ {
			for j := 0; j < len(arr); j++ {
				sums[i+j] = arr[i] + arr[j]
			}
		}
		sort.Ints(sums)

		m := 0
		for i := 0; i < len(sums); i++ {
			rem := M - sums[i]
			if rem >= 0 {
				index := sort.Search(len(sums), func(i int) bool { return sums[i] > rem }) - 1
				if index >= 0 {
					m = max(m, sums[i]+sums[index])
				}
			}
		}
		fmt.Println(m)
	}
}

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

#define pb(n) push_back(n)
#define fi first
#define se second
#define all(r) (r).begin(),(r).end()
#define gsort(st,en) sort((st),(en),greater<int>())
#define vmax(ary) *max_element(all(ary))
#define vmin(ary) *min_element(all(ary))
#define debug(x) cout<<#x<<": "<<x<<endl
#define fcout(n) cout<<fixed<<setprecision((n))
#define scout(n) cout<<setw(n)
#define vary(type,name,size,init) vector< type> name(size,init)

#define rep(i,n) for(int i = 0; i < (int)(n);++i)
#define REP(i,a,b) for(int i = (a);i < (int)(b);++i)
#define repi(it,array) for(auto it = array.begin(),end = array.end(); it != end;++it)
#define repa(n,array) for(auto &n :(array))

using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using dict = map<string,int>;
using pii = pair<int,int> ;
using pll = pair<ll,ll> ;

const int mod = 1000000007;
constexpr int imax = ((1<<30)-1)*2+1 ;
constexpr int inf = 100;
constexpr double PI = acos(-1.0) ;
double eps = 1e-10 ;
const int dy[] = {-1,0,1,0};
const int dx[] = {0,-1,0,1};

inline bool value(int x,int y,int w,int h){
  return (x >= 0 && x < w && y >= 0 && y < h);
}

template<typename T>
void Unique(vector<T> &v){
  sort(all(v));
  v.erase(unique(all(v)),v.end());
}

template<typename T>
T ston(string& str, T n){
  istringstream sin(str) ;
  T num ;
  sin >> num ;
  return num ;
}

void Ans(bool f){
  if(f) cout << "YES"<<endl;
  else cout << "NO"<<endl;
}


int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll n,m;
  while(cin >> n >> m && n && m){
    vary(ll,s,n,0);
    rep(i,n){
      cin >> s[i];
    }
    sort(all(s));
    vector<vector<ll>> dp(5,vector<ll>(n+1,0));
    rep(i,4){
      rep(k,n){
        rep(j,n){
          if(dp[i][k] + s[j] <= m){
            dp[i+1][j] = max(dp[i+1][j],dp[i][k]+s[j]);
          }
        }
      }
    }
//     rep(i,5){
//       rep(j,n){
//         cout << dp[i][j] << " ";
//       }
//       cout << endl;
//     }
    ll ans = 0;
    rep(i,5){
      rep(j,n){
        ans = max(ans,dp[i][j]);
      }
    }
    cout << ans << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;

int m, n, p[1001], pp[1001*1001];

int main(){
    while( true ){
        cin >> n >> m;
        if( m == 0 && n == 0 ) break;
        for(int i = 0; i < n; i++){
            cin >> p[i];
        }
        p[n] = 0;
        n++;
        for(int i = 0; i < n*n; i++){
            pp[i] = p[i/n] + p[i%n];
        }
        sort(pp, pp + n*n);
        int cand = 0;
        int j = n*n-1;
        for(int i = 0; i <= j; i++){
            while( j >= 0 && pp[i] + pp[j] > m ) j--;
            if(j >= 0){
                cand = max(cand, pp[i] + pp[j]);
            }
        }
        cout << cand << endl;
    }
    return 0;
}

C++: #include <iostream>
using namespace std;

int main() {
	for(;;){
		/*入力*/
		int N,M;
		cin >> N >> M;
		if(N==0 && M==0)exit(0);
		int P[N+1],array[M+1]={0};
		P[0]=0;
		for(int i=1;i<=N;i++)cin >> P[i];
		for(int i=0;i<=N;i++)array[P[i]]=1;
		
		
		/*２投(０投１投を含む)で1からMまでが可能か判定*/
		for(int i=0;i<=N;i++){
			for(int j=0;j<=N;j++){
				if(P[i]+P[j] <= M)array[P[i]+P[j]]=1;
			}
		}
		
		/*４投に拡張*/
		int p[M+1]={0};
		for(int i=1;i<=M;i++){
				if(array[i]==1)p[i]=i;
		}
		for(int i=0;i<=M;i++){
			for(int j=0;j<=M;j++){
				if(p[i]+p[j] <= M)array[(p[i]+p[j])]=1;
			}
		}
		
		/*判定出力*/
		for(int i=M;i>0;i--){
			if(array[i]==1){
				cout << i << endl;
				break;
			}
		}
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
vector<long int> po;
long int n,a,low,m,lastans,memo[1005],ss;
void solve(int dp,long int sum);

int main(){
    while(1){
        ss=0;
        lastans=0;
        po.clear();
        low=100000000;
        for(int i=0;i<1005;i++)memo[i]=0;

        cin >> n >> m;
        if(n==0&&m==0)break;
        for(int i=0;i<n;i++){
            cin >> a;
            po.push_back(a);
            low=min(low,a);
        }
        //sort(po.begin(),po.end());
        //cout << po[0] << endl;
        solve(0,0);
        cout << lastans << endl;
        //cout <<"ss=" << ss << endl;
    }

    return 0;
}

void solve(int dp,long int sum){
    //long int ans=0;
    //ss++;
    //cout <<"ss=" << ss << endl;
    if(dp==4)return ;
    else{
    // memo[dp]=max(sum,memo[dp]);

     for(int i=0;i<n;i++){
        if(sum+po[i]<m){
            lastans=max(lastans,sum+po[i]);
            //ans=max(ans,sum+po[i]);
            solve(dp+1,sum+po[i]);
            };
        }
    }
    return;
}

C++: #include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

int n, m;
vector<int> p;
int t;
vector<int> q;
vector<int> o;
int ans;

int b(int x){
	int l = 0;
	int r = q.size();
	while(r - l > 1){
		int i = (l + r) / 2;
//		printf("l=%d, r=%d, i=%d, q[i]=%d, x=%d\n", l, r, i, q[i], x);
		if(q[i] <= x){
			l = i;
		}else{
			r = i;
		}
	}
//	printf("%d\n", q[l]);
	return q[l];
}

int main(){
	while(1){
		scanf("%d %d", &n, &m);
		if(n == 0 && m == 0) break;
		p = o;
		p.push_back(0);
		for(int i=0; i<n; i++){
			scanf("%d", &t);
			p.push_back(t);
		}
		q = o;
		ans = 0;

		for(int i=0; i<p.size(); i++){
			for(int j=0; j<p.size(); j++){
				q.push_back(p[i] + p[j]);
			}
		}
		sort(q.begin(), q.end());
/*
		for(int i=0; i<q.size(); i++)
			printf("%d\n", q[i]);
*/
		for(int i=0; i<q.size(); i++){
			int a = q[i];
			if(m - a < 0) continue;
			ans = max(ans, b(m - a) + a);
//			printf("%d\n", b(m - a));
		}

		printf("%d\n", ans);
	}

	return 0;
}

C++: #include <iostream>
#include <string.h>
#include <algorithm>
#include <set>
#include <cstdio>
using namespace std;

int main() {
	int N, M;
	while(cin >> N >> M && (N || M)){
		int  P[1001] = {0}, ans = 0;
		for(int i = 0; i < N; ++i){
			scanf("%d", &P[i]);
		}
		set<int> darts;
		for(int i = 0; i <= N; ++i){
			for(int j = 0; j <= N; ++j){
				if(P[i] + P[j] > M)
					continue;
				darts.insert(P[i] + P[j]);
			}
		}
		for(int i = 0; i < N; ++i){
			for(int j = 0; j < N; ++j){
				if(P[i] + P[j] > M)
					continue;
				set<int>::iterator it = darts.lower_bound(M - (P[i] + P[j]));
				if(it == darts.end())
					--it;
				if(*it > M - (P[i] + P[j]))
					--it;
					
				ans = max(ans, P[i] + P[j] + *it);
			}
		}
		cout << ans << endl;
	}
	return 0;
}