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>
using namespace std;

const int E = 100000;
int par[E], rank1[E];
struct Edge { int u, v, cost; };

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

Edge edge[E];

void init(int n)
{
	for(int i = 0; i < n; ++i){
		par[i] = i;
		rank1[i] = 0;
	}
}

int find(int x)
{
	if(x == par[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(rank1[x] > rank1[y])
		par[y] = x;
	else {
		par[x] = y;
		if(rank1[x] == rank1[y])
			rank1[x] ++;
	}
}

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

int main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	int v, e;
	cin >> v >> e;
	init(v);
	
	int s, t, w;
	for(int i = 0; i < e; ++i){
		cin >> s >> t >> w;
		edge[i] = Edge{ s, t, w };
	}
	
	sort(edge, edge + e, comp);
	
	int ans = 0;
	for(int i = 0; i < e; ++i){
		Edge e1 = edge[i];
		if(!same(e1.u, e1.v)){
			unite(e1.u, e1.v);
			ans += e1.cost;
		}
	}
	
	cout << ans << endl;
	
	return 0;
}