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

#define dump(...) cout<<"# "<<#__VA_ARGS__<<'='<<(__VA_ARGS__)<<endl
#define repi(i,a,b) for(int i=int(a);i<int(b);i++)
#define peri(i,a,b) for(int i=int(b);i-->int(a);)
#define rep(i,n) repi(i,0,n)
#define per(i,n) peri(i,0,n)
#define all(c) begin(c),end(c)
#define mp make_pair
#define mt make_tuple

typedef unsigned int uint;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<string> vs;

constexpr int INF=1e9;
constexpr int MOD=1e9+7;
constexpr double EPS=1e-9;

template<typename T1,typename T2>
ostream& operator<<(ostream& os,const pair<T1,T2>& p){
	return os<<'('<<p.first<<','<<p.second<<')';
}
template<typename Ostream,typename Container>
Ostream& operator<<(Ostream& os,const Container& c){
	os<<'[';
	for(auto i=begin(c);i!=end(c);++i)
		os<<(i==begin(c)?"":" ")<<*i;
	return os<<']';
}

struct UnionFind{
	vi data;
	UnionFind(int n):data(n,-1){}
	int Find(int i){
		return data[i]<0?i:(data[i]=Find(data[i]));
	}
	bool Unite(int a,int b){
		a=Find(a),b=Find(b);
		if(a==b) return false;
		if(-data[a]<-data[b]) swap(a,b);
		data[a]+=data[b];
		data[b]=a;
		return true;
	}
	int Size(int i){
		return -data[Find(i)];
	}
};

struct Edge{
	int src,dst,weight;
	Edge(){}
	Edge(int s,int d,int w):src(s),dst(d),weight(w){}
};
typedef vector<vector<Edge>> Graph;
bool operator<(const Edge& a,const Edge& b){return a.weight<b.weight;}
bool operator>(const Edge& a,const Edge& b){return a.weight>b.weight;}

int Kruskal(const Graph& g,vector<Edge>& forest)
{
	int n=g.size();
	vector<Edge> es;
	rep(i,n) es.insert(end(es),all(g[i]));
	sort(all(es));
	
	UnionFind uf(n);
	int res=0;
	for(auto e:es)
		if(uf.Unite(e.src,e.dst)){
			res+=e.weight;
			forest.push_back(e);
		}
	return res;
}

int main()
{
	for(int n,m;cin>>n>>m && n|m;){
		Graph g(n);
		rep(i,m){
			int u,v,w; cin>>u>>v>>w; u--,v--;
			g[u].emplace_back(u,v,w);
		}
		vector<Edge> tree;
		Kruskal(g,tree);
		cout<<tree[n/2-1].weight<<endl;
	}
}
### Prompt

Construct a CPP code solution to the problem outlined:

Problem Statement

You are given a connected undirected graph which has even numbers of nodes. A connected graph is a graph in which all nodes are connected directly or indirectly by edges.

Your task is to find a spanning tree whose median value of edges' costs is minimum. A spanning tree of a graph means that a tree which contains all nodes of the graph.



Input

The input consists of multiple datasets.

The format of each dataset is as follows.


n m
s_1 t_1 c_1
...
s_m t_m c_m


The first line contains an even number n (2 \leq n \leq 1,000) and an integer m (n-1 \leq m \leq 10,000). n is the nubmer of nodes and m is the number of edges in the graph.

Then m lines follow, each of which contains s_i (1 \leq s_i \leq n), t_i (1 \leq s_i \leq n, t_i \neq s_i) and c_i (1 \leq c_i \leq 1,000). This means there is an edge between the nodes s_i and t_i and its cost is c_i. There is no more than one edge which connects s_i and t_i.

The input terminates when n=0 and m=0. Your program must not output anything for this case.

Output

Print the median value in a line for each dataset.

Example

Input

2 1
1 2 5
4 6
1 2 1
1 3 2
1 4 3
2 3 4
2 4 5
3 4 6
8 17
1 4 767
3 1 609
8 3 426
6 5 972
8 1 607
6 4 51
5 1 683
3 6 451
3 4 630
8 7 912
3 7 43
4 7 421
3 5 582
8 4 538
5 7 832
1 6 345
8 2 608
0 0


Output

5
2
421

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;

#define dump(...) cout<<"# "<<#__VA_ARGS__<<'='<<(__VA_ARGS__)<<endl
#define repi(i,a,b) for(int i=int(a);i<int(b);i++)
#define peri(i,a,b) for(int i=int(b);i-->int(a);)
#define rep(i,n) repi(i,0,n)
#define per(i,n) peri(i,0,n)
#define all(c) begin(c),end(c)
#define mp make_pair
#define mt make_tuple

typedef unsigned int uint;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<string> vs;

constexpr int INF=1e9;
constexpr int MOD=1e9+7;
constexpr double EPS=1e-9;

template<typename T1,typename T2>
ostream& operator<<(ostream& os,const pair<T1,T2>& p){
	return os<<'('<<p.first<<','<<p.second<<')';
}
template<typename Ostream,typename Container>
Ostream& operator<<(Ostream& os,const Container& c){
	os<<'[';
	for(auto i=begin(c);i!=end(c);++i)
		os<<(i==begin(c)?"":" ")<<*i;
	return os<<']';
}

struct UnionFind{
	vi data;
	UnionFind(int n):data(n,-1){}
	int Find(int i){
		return data[i]<0?i:(data[i]=Find(data[i]));
	}
	bool Unite(int a,int b){
		a=Find(a),b=Find(b);
		if(a==b) return false;
		if(-data[a]<-data[b]) swap(a,b);
		data[a]+=data[b];
		data[b]=a;
		return true;
	}
	int Size(int i){
		return -data[Find(i)];
	}
};

struct Edge{
	int src,dst,weight;
	Edge(){}
	Edge(int s,int d,int w):src(s),dst(d),weight(w){}
};
typedef vector<vector<Edge>> Graph;
bool operator<(const Edge& a,const Edge& b){return a.weight<b.weight;}
bool operator>(const Edge& a,const Edge& b){return a.weight>b.weight;}

int Kruskal(const Graph& g,vector<Edge>& forest)
{
	int n=g.size();
	vector<Edge> es;
	rep(i,n) es.insert(end(es),all(g[i]));
	sort(all(es));
	
	UnionFind uf(n);
	int res=0;
	for(auto e:es)
		if(uf.Unite(e.src,e.dst)){
			res+=e.weight;
			forest.push_back(e);
		}
	return res;
}

int main()
{
	for(int n,m;cin>>n>>m && n|m;){
		Graph g(n);
		rep(i,m){
			int u,v,w; cin>>u>>v>>w; u--,v--;
			g[u].emplace_back(u,v,w);
		}
		vector<Edge> tree;
		Kruskal(g,tree);
		cout<<tree[n/2-1].weight<<endl;
	}
}
```