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>
#include <vector>
#include <string>
#include <utility>
#include <iterator>
using namespace std;

struct UnionFind {
    vector<int> data;
    UnionFind(int n) : data(n, -1) { }
    int root(int x) {
        return data[x] < 0 ? x : data[x] = root(data[x]);
    }
    bool same(int x, int y) { return root(x) == root(y); }
    void merge(int x, int y) {
        x = root(x); y = root(y);
        if(x != y) {
            data[x] += data[y];
            data[y] = x;
        }
    }
};

int main() {
    int V, E; cin >> V >> E;
    vector<pair<int, pair<int, int> > > ES(E);
    for(int i = 0; i < E; i++) {
        cin >> ES[i].second.first >> ES[i].second.second >> ES[i].first;
    }
    sort(begin(ES), end(ES));
    int ans = 0;
    UnionFind uf(V);
    for(auto item : ES) {
        if(uf.same(item.second.first, item.second.second) == false) {
            ans += item.first;
            uf.merge(item.second.first, item.second.second);
        }
    }
    cout << ans << endl;
}