#include "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "string"
#include "map"
#include "unordered_map"
#include "unordered_set"
#include "iomanip"
#include "cmath"
#include "random"
#include "bitset"
#include "cstdio"
#include "numeric"
#include "cassert"
#include "ctime"

using namespace std;

//constexpr long long int MOD = 1000000007;
//constexpr int MOD = 1000000007;
//constexpr int MOD = 998244353;
constexpr long long int MOD = 998244353;
constexpr double EPS = 1e-9;

//int N, M, K, H, W, L, R;
long long int N, M, K, H, W, L, R;

class UnionFind {
	vector<int>parent;
	vector<int>rank;
public:
	UnionFind(int num) {
		num++;
		parent.resize(num);
		rank.resize(num);
		for (int i = 0; i < num; i++) {
			parent[i] = i;
			rank[i] = 0;
		}
	}
	int Find(int node) {
		if (parent[node] == node)return node;
		else return parent[node] = Find(parent[node]);
	}
	void Unite(int u, int v) {
		u = Find(u);
		v = Find(v);
		if (u == v)return;
		if (rank[u] < rank[v])parent[u] = v;
		else {
			parent[v] = u;
			if (rank[u] == rank[v])rank[u]++;
		}
	}
	bool Check_Same(int u, int v) {
		return Find(u) == Find(v);
	}
};

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

	while (cin >> N >> M, N) {
		UnionFind uf(N);
		vector<pair<int, pair<int, int>>>v(M);
		for (auto &i : v)cin >> i.second.first >> i.second.second >> i.first;
		sort(v.begin(), v.end());
		int used = 0;
		for (auto i : v) {
			if (uf.Check_Same(i.second.first, i.second.second))continue;
			used++;
			uf.Unite(i.second.first, i.second.second);
			if (used * 2 == N) {
				cout << i.first << endl;
			}
		}
	}
}

### Prompt

Please provide a cpp coded solution to the problem described below:

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 "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "string"
#include "map"
#include "unordered_map"
#include "unordered_set"
#include "iomanip"
#include "cmath"
#include "random"
#include "bitset"
#include "cstdio"
#include "numeric"
#include "cassert"
#include "ctime"

using namespace std;

//constexpr long long int MOD = 1000000007;
//constexpr int MOD = 1000000007;
//constexpr int MOD = 998244353;
constexpr long long int MOD = 998244353;
constexpr double EPS = 1e-9;

//int N, M, K, H, W, L, R;
long long int N, M, K, H, W, L, R;

class UnionFind {
	vector<int>parent;
	vector<int>rank;
public:
	UnionFind(int num) {
		num++;
		parent.resize(num);
		rank.resize(num);
		for (int i = 0; i < num; i++) {
			parent[i] = i;
			rank[i] = 0;
		}
	}
	int Find(int node) {
		if (parent[node] == node)return node;
		else return parent[node] = Find(parent[node]);
	}
	void Unite(int u, int v) {
		u = Find(u);
		v = Find(v);
		if (u == v)return;
		if (rank[u] < rank[v])parent[u] = v;
		else {
			parent[v] = u;
			if (rank[u] == rank[v])rank[u]++;
		}
	}
	bool Check_Same(int u, int v) {
		return Find(u) == Find(v);
	}
};

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

	while (cin >> N >> M, N) {
		UnionFind uf(N);
		vector<pair<int, pair<int, int>>>v(M);
		for (auto &i : v)cin >> i.second.first >> i.second.second >> i.first;
		sort(v.begin(), v.end());
		int used = 0;
		for (auto i : v) {
			if (uf.Check_Same(i.second.first, i.second.second))continue;
			used++;
			uf.Unite(i.second.first, i.second.second);
			if (used * 2 == N) {
				cout << i.first << endl;
			}
		}
	}
}

```