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 JAVA):

Solution:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.PriorityQueue;
import java.util.Queue;

public class Main {

	public static void main(String args[]) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String str[] = br.readLine().split(" ");
		int V = Integer.parseInt(str[0]);
		int E = Integer.parseInt(str[1]);

		ArrayList<ArrayList<Edge>> edges = new ArrayList<>();

		for (int i = 0; i < V; i++) {
			edges.add(new ArrayList<>());
		}

		for (int i = 0; i < E; i++) {
			str = br.readLine().split(" ");
			int s = Integer.parseInt(str[0]);
			int t = Integer.parseInt(str[1]);
			int w = Integer.parseInt(str[2]);

			edges.get(s).add(new Edge(t, w));
			edges.get(t).add(new Edge(s, w));
		}

		int sum = prime(edges, V);
		System.out.println(sum);
	}

	static int prime(ArrayList<ArrayList<Edge>> edges, int n) {
		boolean[] done = new boolean[n]; // 訪問フラグ

		Queue<Edge> q = new PriorityQueue<Edge>();
		q.add(new Edge(0, 0)); // ０から(ダミー)

		int totalCost = 0; // 最小全域木の重み
		while (!q.isEmpty()) {
			Edge e = q.poll(); // 最小コストの辺を取り出す
			if (done[e.to]) {
				continue;
			}

			done[e.to] = true; // 訪問済にする
			totalCost += e.cost;
			q.addAll(edges.get(e.to)); // 隣接しているすべての辺を追加
		}

		return totalCost;
	}
}

class Edge implements Comparable<Edge> {

	int to;
	int cost;

	public Edge(int to, int cost) {
		this.to = to;
		this.cost = cost;
	}

	@Override
	public int compareTo(Edge e) {
		return this.cost - e.cost;
	}
}