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<bits/stdc++.h>

using namespace std;
using ll = long long;


int prim(int start, vector<vector<pair<int,int>>> hen) {

    priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> que;
    que.emplace(0, start);
    vector<int> seen(hen.size());
    int sum = 0;

    while(que.size()) {
        int cost = que.top().first, vert = que.top().second;
        que.pop();
        if(seen[vert])continue;
        seen[vert] = true;
        //処理をする
        sum += cost;

        for(auto i : hen[vert]) {
            if(seen[i.first])continue;
            que.emplace(i.second, i.first);

        }
    }
    return sum;
}


int main()
{
    int n, m;
    cin >> n >> m;
    vector<vector<pair<int,int>>> hen(n);
    for(int i = 0; i < m; i++) {
        int a, b, c; cin >> a >> b >> c;
        hen[a].emplace_back(b, c);
        hen[b].emplace_back(a, c);
    }
    cout << prim(0, hen) << endl;
}