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;

struct UnionFind{
  int n;
  vector<int> r,p;
  UnionFind(){}
  UnionFind(int sz):n(sz),r(sz,1),p(sz,0){iota(p.begin(),p.end(),0);}
  int find(int x){
    return (x==p[x]?x:p[x]=find(p[x]));
  }
  bool same(int x,int y){
    return find(x)==find(y);
  }
  void unite(int x,int y){
    x=find(x);y=find(y);
    if(x==y) return;
    if(r[x]<r[y]) swap(x,y);
    r[x]+=r[y];
    p[y]=x;
  }
};

int main(){
  int V,E;
  cin>>V>>E;
  std::vector<int> s(E),t(E),w(E);
  for(int i=0;i<E;i++)cin>>s[i]>>t[i]>>w[i];
  typedef tuple<int,int,int> X;
  std::vector<X> x(E);
  for(int i=0;i<E;i++)x[i]=X(w[i],s[i],t[i]);
  sort(x.begin(),x.end());
  int ans=0;
  UnionFind uf(V);
  for(int i=0;i<E;i++){
    int& ww=std::get<0>(x[i]);
    int& ss=std::get<1>(x[i]);
    int& tt=std::get<2>(x[i]);
    if(!uf.same(ss,tt)){
      ans+=ww;
      uf.unite(ss,tt);
    }
  }
  cout<<ans<<endl;
}