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;
typedef pair<int, int> P;
const int INF = 1e9;
const int MAX_V = 100000;

struct edge{
   int to, cost;
};

vector<edge> G[MAX_V];
bool used[MAX_V];
int n, m;

int prim(){
    int res = 0;
    priority_queue<P, vector<P>, greater<P> > q;
    memset(used, false, sizeof(used));
    q.push(P(0, 0));
    while(!q.empty()){
        P p = q.top(); q.pop();
        int v = p.second;
        int d = p.first;
        if(used[v]) continue;
        used[v] = true;
        res += d;
        for(int i = 0; i < G[v].size(); i++){
            q.push(P(G[v][i].cost, G[v][i].to));
        }
    }
    return res;
}

int main(){
    cin >> n >> m;
    for(int i = 0; i < m; i++){
        int s, t, w;
        cin >> s >> t >> w;
        //s--; t--;
        G[s].push_back({t, w});
        G[t].push_back({s, w});
    }
    cout << prim() << endl;
}

/* verified
https://onlinejudge.u-aizu.ac.jp/#/courses/library/5/GRL/2/GRL_2_A
*/