Problem: Find the sum of weights of edges of the Minimum Spanning Tree for a given weighted undirected graph G = (V, E).

Constraints

* 1 ≤ |V| ≤ 10,000
* 0 ≤ |E| ≤ 100,000
* 0 ≤ wi ≤ 10,000
* The graph is connected
* There are no parallel edges
* There are no self-loops

Input


|V| |E|
s0 t0 w0
s1 t1 w1
:
s|E|-1 t|E|-1 w|E|-1


, where |V| is the number of vertices and |E| is the number of edges in the graph. The graph vertices are named with the numbers 0, 1,..., |V|-1 respectively.

si and ti represent source and target verticess of i-th edge (undirected) and wi represents the weight of the i-th edge.

Output

Print the sum of the weights of the Minimum Spanning Tree.

Examples

Input

4 6
0 1 2
1 2 1
2 3 1
3 0 1
0 2 3
1 3 5


Output

3


Input

6 9
0 1 1
0 2 3
1 2 1
1 3 7
2 4 1
1 4 3
3 4 1
3 5 1
4 5 6


Output

5

Solution (in CPP):

Solution:
#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
const int MAX = 10000;
const int INF = 999999999;
int U[MAX];
int n, G[MAX][MAX];
struct Edge
{
	int u;
	int v;
	int w;
};
vector<Edge> E;
void init()
{
	for (int i = 0; i < n; i++)
		U[i] = i;
}
int getAncestor(int v)
{
	if (U[v] == v)
		return v;
	else
	{
		U[v] = getAncestor(U[v]);
		return U[v];
	}
}
bool merge(int s, int t)
{
	int a1 = getAncestor(s);
	int a2 = getAncestor(t);
	if (a1 != a2)
	{
		U[a2] = a1;
		return false;
	}
	return true;
}
bool cmp(Edge a, Edge b)
{
	return a.w < b.w;
}
int main()
{
	int m;
	cin >> n >> m;
	for (int i = 0; i < m; i++)
	{
		int u, v, w;
		cin >> u >> v >> w;
		Edge e = { u,v,w };
		E.push_back(e);
	}
	init();
		sort(E.begin(), E.end(), cmp);
	int sum = 0;
	int edgeNum = 0;
	//cout << "MST的边为：\n";
	for (int i = 0; i < E.size(); i++)
	{
		Edge e = E[i];
		if (!merge(e.u, e.v))
		{
			sum += e.w;
			edgeNum++;
			//cout << e.u << "---" << e.v << " 权值为" << e.v << endl;
		}
		if (edgeNum == n - 1)
			break;
	}
	cout << sum << endl;
}