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:
// AOJ
// Minimum Spanning Tree
// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_2_A&lang=ja
#include <bits/stdc++.h>
using namespace std;

int main()
{
    int V, E; cin >> V >> E;
    vector< vector<pair<int, int>> > g(V);
    for (int i = 0; i < E; i++) {
        int s, t, w; cin >> s >> t >> w;
        g[s].push_back(make_pair(w, t));
        g[t].push_back(make_pair(w, s));
    }

    int total_weight = 0;
    vector<bool> done(V, false);
    priority_queue<
        pair<int, int>,
        vector<pair<int, int>>,
        greater<pair<int, int>>
    > q;
    q.push(make_pair(0, 0));
    while (!q.empty()) {
        pair<int, int> e = q.top(); q.pop();
        int& w = e.first, v = e.second;
        if (done[v]) continue;
        total_weight += w;
        done[v] = true;
        for (const auto& f : g[v]) {
            if (!done[f.second])
                q.push(f);
        }
    }
    cout << total_weight << endl;
}