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 N=1e4;
int n,m,ans;
vector <pair <int, pair <int, int> > > g;
vector <pair <int, int> > MST;
int parent [N];
 
int root (int a){
    if(parent[a] ==a)
        return a;
    parent[a]=root(parent[a]);
    return root(parent[a]);
}
 
void Union (int a,int b){
    parent[root(a)]=root(b);
}
 
void find_mst(){
	sort (g.begin (), g.end ());
	MST.clear();
	for(int i=0; i<n; i++)
	    parent[i]=i;
	for(int i=0; i<m; i++){
		int f=g[i].second.first;
		int t=g[i].second.second;
		if(root(f)!=root(t)){
		    MST.push_back(g[i].second);
		    ans+=g[i].first;
			Union(f,t);
		}
	}
}
 
int main() {
	cin >> n>>m;
	g.clear();
	for(int i=0; i<m; i++){
		int f,t,w;
		cin >>f>>t>>w;
		g.push_back(make_pair (w, make_pair (f,t)));
	}
    find_mst();	
    cout << ans << endl;
}