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>
#define MAX_V 10005
using namespace std;
typedef long long lint;
typedef pair<int,int> P;
const int INF=(int)1e9;
const int MOD=(int)1e9+7;
struct Accelerate_Cin{
    Accelerate_Cin(){
        cin.tie(0); ios::sync_with_stdio(0); cout<<fixed<<setprecision(20);
    };
};

//Ｏ(|E|log|V|)
vector<P> G[MAX_V]; //G[v]=P(w,i):=頂点ｖとiの間の辺の重さがｗ
bool used[MAX_V];   //used[i]=:頂点iをすでに通ったかどうか

int prim(){
  int res=0;        //res=:最小全域木の辺の重さの総和
  priority_queue<P,vector<P>,greater<P> > q;
  memset(used,0,sizeof(used));

  q.push(P(0,0));
  while(!q.empty()){
    P p=q.top();q.pop();
    int d=p.first,v=p.second;    //first:辺の重さ、second:次の頂点
    if(used[v]) continue;
    used[v]=1;
    res+=d;
    for(int i=0;i<(int)G[v].size();i++){
      q.push(G[v][i]);
    }
  }
  return res;
}


int main(){
  int V,E;
  cin>>V>>E;
  for(int i=0;i<E;i++){
    int s,t,w;
    cin>>s>>t>>w;
    G[s].push_back(P(w,t));
    G[t].push_back(P(w,s));
  }

 cout<<prim()<<endl;
 return 0;
}