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.util.*;

// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_2_A&lang=jp
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int V = sc.nextInt();
        int E = sc.nextInt();

        @SuppressWarnings("unchecked")
        List<Edge>[] edges = new ArrayList[V];
        for (int i = 0; i < V; i++) {
            edges[i] = new ArrayList<>();
        }
        for (int i = 0; i < E; i++) {
            int s = sc.nextInt();
            int t = sc.nextInt();
            int w = sc.nextInt();
            edges[s].add(new Edge(s, t, w));
            edges[t].add(new Edge(t, s, w));
        }

        boolean[] done = new boolean[V];
        Arrays.fill(done, false);
        Queue<Edge> q = new PriorityQueue<>();
        q.add(new Edge(0, 0, 0));
        int costSum = 0;
        while (!q.isEmpty()) {
            Edge e = q.poll();
            if (done[e.t]) {
                continue;
            }
            done[e.t] = true;
            costSum += e.w;
            q.addAll(edges[e.t]);
        }
        System.out.println(costSum);
    }

    public static class Edge implements Comparable<Edge> {
        public int s, t, w;

        Edge(int s, int t, int w) {
            this.s = s;
            this.t = t;
            this.w = w;
        }

        @Override
        public int compareTo(Edge o) {
            return this.w - o.w;
            // return o.w - this.w;
        }
    }
}