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 <queue>
#include <set>
#include <map>
#include <vector>
#define FOR(i,n) for(unsigned i=0; i<n; i++)

using namespace std;

typedef unsigned us;
typedef pair<us, us> point;

int main () {
    us V, E;
    cin >> V >> E;

    set<us> seen;
    seen.insert(0);
    map<us, vector<point> > graph;
    priority_queue<point, vector<point>, greater<point> > q;
    us distance = 0;

    FOR(_, E) {
        us s, t, d;
        cin >> s >> t >> d;
        graph[s].push_back(make_pair(d, t));
        graph[t].push_back(make_pair(d, s));
        if (s == 0) q.push(make_pair(d, t));
        if (t == 0) q.push(make_pair(d, s));
    }

    while (!q.empty() && seen.size() != V) {
        point p = q.top();
        us v = p.second;
        us w = p.first;
        q.pop();

        if (seen.find(v) == seen.end()) {
            seen.insert(v);
            vector<point> neighbours = graph[v];
            FOR(i, neighbours.size()) q.push(neighbours[i]);
            distance += w;
        }
    }

    cout << distance << endl;

}