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<bits/stdc++.h>
using namespace std;
#define mx 1000000007
#define F first //コスト
#define SF second.first //始め
#define SS second.second //終わり
typedef pair<int,int> P;
typedef pair<int,P> PP;
int main()
{
	int n,m,s;
	int a,b,c;
	int i,j;
	
	PP p[100000];
	
	cin>>n>>m;
	int d[n];
	
	for(i=0;i<m;i++){
		cin>>a>>b>>c;
		p[i]=PP(c,P(a,b));	
	}
	
	sort(p,p+m);

	
	int leng[10000],par[10000];
	for(i=0;i<n;i++){
		leng[i]=1; par[i]=i; d[i]=mx;
	}
	d[s]=0;
	
	int sum=0,x,y;
	for(i=0;i<m;i++){
	
		d[p[i].SS]=min(d[p[i].SS],d[p[i].SF]+p[i].F);
		
		x=p[i].SF;
		while(x!=par[x]) x=par[x];
		
		y=p[i].SS;
		while(y!=par[y]) y=par[y];
		
		
		if(x==y) continue;
		
		else {
			if(leng[x]>leng[y]) par[y]=x;
			
			else if(leng[x]<leng[y]) par[x]=y;
			
			else {par[y]=x,leng[x]++;}
			sum+=p[i].F;
		}
	}
	
	cout<<sum<<endl;
	
	return 0;
}