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 <queue>
using namespace std;
const int MAX_V=10000;
typedef pair<int,int> P;
vector<P> G[MAX_V];
bool f[MAX_V];
int v;
int prim(){
  int r=0;
  priority_queue<P,vector<P>,greater<P> > q;
  q.push(P(0,0));
  fill(f,f+v,0);
  for(;!q.empty();){
    P p=q.top();q.pop();
    int b=p.second,d=p.first;
    if(f[b]) continue;
    f[b]=1;
    r+=d;
    for(int i=0;i<(int)G[b].size();i++) q.push(G[b][i]);
  }
  return r;
}
int main(){
  int e;
  cin>>v>>e;
  for(int i=0,a,b,c;i<e&&cin>>a>>b>>c;i++) G[a].push_back(P(c,b)),G[b].push_back(P(c,a));
  cout<<prim()<<endl;
  return 0;
}