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>

int search_root(int *par, int v)
{

  if(par[v] != v) 
    {
      par[v] = search_root(par, par[v]);
      return par[v];
    }
  else
    return v;

}

int unite(int *par, int v1, int v2)
{
  int r1 = search_root(par, v1);
  int r2 = search_root(par, v2);
    
  if(r1 != r2)
    {
      par[r1] = r2;
      return true;
    }

  else
    return false;
}

int main(int argc, char **argv)
{
  int Vnum,Enum,i;

  std::cin >> Vnum >> Enum;

  int *par, *s, *t;
  s = new int[Enum];
  t = new int[Enum];
  par = new int[Vnum];
  std::pair<int,int> w[Enum];
  
  for(i=0; i<Enum; i++)
    {
      std::cin >> s[i] >> t[i] >> w[i].first;
      w[i].second = i;
    }

  std::sort(w, w+Enum);

  for(i=0; i<Vnum; i++)
    par[i]=i;
      
  int sum = 0;

  for(i=0; i<Enum; i++)
    {
      if(unite(par, s[w[i].second], t[w[i].second]))
	sum += w[i].first;
    }
      
  std::cout << sum << std::endl;

  return 0;
}