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>
using namespace std;


const int MAX_V = 10000;
const int MAX_E = 100000;
int finde[MAX_V];

struct Edge {
	int first;
	int second;
	int weight;
};
vector<Edge> e;

bool operator < (const Edge& a, const Edge& b) {
	return a.weight < b.weight;
}

bool Judge(int m, int n) {
	while (finde[m] != m) m = finde[m];
	while (finde[n] != n) n = finde[n];
	if (m == n) {
		return false;
	}
	 finde[n]= m;
	return true;
}

int min_span_tree(int n, int m) {

	for (int i = 0; i < m; i++) finde[i] = i;
	int count = 0;
	int ret = 0;
	int f, s;
	for (int i = 0;count<m-1; i++) {
		f = e[i].first;
		s = e[i].second;
		if (Judge(f,s)) {		
			ret += e[i].weight;
			count++;
		}
	}
	return ret;
}
int main() {
	int n, m;
	cin >> m >> n;
	for (int i = 0; i < n; i++) {
		int s, t, w;
		cin>>s>>t>>w;
		e.push_back(Edge{ s, t, w });
	}
	sort(e.begin(), e.end());
	int ret = min_span_tree(n, m);
	cout << ret << endl;
	return 0;
}