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 <vector>
#include <queue>
#include <utility>
using namespace std;
const int INF = (1e9);

int prim(vector< vector< pair<int,int> > > &G){
  vector<bool> connected(G.size(),false);
  priority_queue< pair<int,int> > wait;
  wait.emplace(0,0);
  int ret = 0;
  while(!wait.empty()){
    int c = -wait.top().first, v = wait.top().second;
    wait.pop();
    if(connected[v]) continue;
    connected[v] = true;
    ret += c;
    for(size_t i = 0; i < G[v].size(); ++i){
      int c_ = G[v][i].first, v_ = G[v][i].second;
      if(!connected[v_]){
        connected[v] = true;
        wait.emplace(-c_,v_);
      }
    }
  }
  return ret;
}

int main(){
  int V, E;
  cin >> V >> E;
  vector< vector< pair<int,int> > > G(V);
  for(int i = 0; i < E; ++i){
    int s, t, d;
    cin >> s >> t >> d;
    G[s].emplace_back(d,t);
    G[t].emplace_back(d,s);
  }
  cout << prim(G) << endl;
  return 0;
}