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;

class Edge {
public:
	int v1, v2, d;
};

int s, t, V[10000];
Edge E[100000];

bool X(const Edge& a, const Edge& b) { return a.d < b.d; }

int Kruskal() {
	int m = 0;
	for (int i = 0; i < t; i++) {
		Edge e = E[i];
		if (V[e.v1] != V[e.v2]) {
			int v = V[e.v1], u = V[e.v2]; m += e.d;
			for (int j = 0; j < s; j++) {
				if (V[j] == u) V[j] = v;
			}
		}
	}
	return m;
}

int main() {
	cin >> s >> t;
	for (int i = 0; i < s; i++) V[i] = i;
	for (int i = 0; i < t; i++) {
		cin >> E[i].v1 >> E[i].v2 >> E[i].d;
	}

	sort(E, E+t, X);

	cout << Kruskal() << endl;
}