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 <cstdio>
#include <algorithm>
#include <iostream>
#include <vector>
#include <string.h>
#include <math.h>
#include <time.h>
#include <stdlib.h>
#include <queue>

#define INF 214748364000

using namespace std;

/*union-find*/
int par[10000],ranks[10000];

void init(int n){
	for(int i=0;i<n;i++){
		par[i] = i;
		ranks[i] = 0;
	}
}

int find(int x){
	if(par[x]==x) return x;
	else return par[x] = find(par[x]);
}

void unite(int x,int y){
	x = find(x);
	y = find(y);
	if(x==y) return ;
	if(ranks[x]< ranks[y]) par[x]=y;
	else{
		par[y] = x;
		if(ranks[x]==ranks[y]) ranks[y]++;
	}
}

bool same(int x,int y){
	return find(x) == find(y);
}
//------------//

struct edge { int from,to,cost;};

bool comp(const edge& e1, const edge& e2){
	return e1.cost < e2.cost;
}

int main(){
	int V,E,
	    s,t,d,sum=0;
	edge G[100000];
	
	scanf("%d %d",&V,&E);
	for(int i=0;i<E;i++){
		scanf("%d %d %d",&s,&t,&d);
		G[i] = {s,t,d};
	}
	
	sort(G,G+E,comp);
	init(V);
	for(int i=0;i<E;i++){
		edge e= G[i];
		if(!same(e.to,e.from)){
			unite(e.to,e.from);
			sum += e.cost;
		}
	}
	printf("%d\n",sum);
	return 0;
}