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<cstdio>
#include<algorithm>
#include<vector>
#include<queue>
using namespace std;

typedef pair<int,int> pii;
const int INF =  1000000000;

int par[10000],rnk[10000];

void init(int n){
  for(int i=0;i<n;i++){
    par[i] = i;
    rnk[i] = 1;
  }
}
int find(int x){
  if(par[x]==x) return x;
  else return par[x] = find(par[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(rnk[x]>rnk[y]) par[y] = x;
  else{
    par[x] = y;
    if(rnk[x]==rnk[y]) rnk[y]++;
  }
  return;
}

int main(){
  int V,E;
  vector<pair<int,pii> > es;
  scanf("%d %d",&V,&E);
  for(int i=0;i<E;i++){
    int s,t,w;
    scanf("%d %d %d",&s,&t,&w);
    es.push_back(make_pair(w,pii(s,t)));
  }
  int ans = 0;
  int cost[10000];
  fill(cost,cost+V,INF);
  sort(es.begin(),es.end());
  cost[0] = 0;
  init(V);
  for(int i=0;i<es.size();i++){
    if(!same(es[i].second.first,es[i].second.second)){
      ans += es[i].first;
      unite(es[i].second.first,es[i].second.second);
    }
  }
  printf("%d\n",ans);
  return 0;
}