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;

#define MAX_V 100000
#define INF 111111111
struct edge{int to,cost;};
typedef pair<int ,int> P; //firstは距離、secondは頂点の番号

int V; //頂点数
vector<edge> G[MAX_V]; //添字がfrom
int d[MAX_V]; //最短コスト

int prim(){
  priority_queue<P,vector<P>,greater<P> > que;
  fill(d,d+V,INF);
  int res=0;
  que.push(P(0,0));
  while(!que.empty()){
    P p=que.top();
    que.pop();
    int v=p.second;
    if(d[v]!=INF)continue;
    res+=p.first;
    d[v]=p.first;
    for(int i=0;i<G[v].size();i++){
      edge e=G[v][i];
      if(d[e.to]==INF)que.push(P(e.cost,e.to));
    }
  }
  return res;
}

int main(){
  int E;
  cin>>V>>E;
  for(int i=0;i<E;i++){
    int s,t,c;
    edge e;
    cin>>s>>t>>c;
    e.to=t,e.cost=c;
    G[s].push_back(e);
    e.to=s;
    G[t].push_back(e);
  }
  cout<<prim()<<endl;
  return 0;
}