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 <algorithm>
#include <vector>
#include <queue>
#include <cassert>

using namespace std;

struct edge { int to, cost; };
typedef pair<int, int> P;

const int MAX_V = 10000;
const int INF = 1 << 28;

int V;
vector<edge> G[MAX_V];
int d[MAX_V];

int prim(){
	int res = 0;
	priority_queue<P, vector<P>, greater<P> > que;
	fill(d, d + V, INF);
	for(int s = 0;s < V; ++s) {
		if(d[s] != INF) continue;
		d[s] = 0;
		que.push(P(0, s));
		while(!que.empty()){
			P p = que.top(); que.pop();
			int v = p.second;
			if(d[v] < p.first) continue;
			d[v] = -1;
			res += p.first;
			for(int i=0;i<G[v].size();i++){
				edge e = G[v][i];
				if(d[e.to] > e.cost){
					d[e.to] = e.cost;
					que.push(P(e.cost, e.to));
				}
			}
		}
	}
	return res;
}

int main(){
	int E;
	cin >> V >> E;
	for(int i=0;i<E;i++){
		int s, t, w;
		cin >> s >> t >> w;
		assert(0 <= s && s < V);
		assert(0 <= t && t < V);
		G[s].push_back((edge){t, w});
		G[t].push_back((edge){s, w});
	}
	cout << prim() << endl;
	return 0;
}