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 <algorithm>

typedef std::pair<int, std::pair<int, int>> EDGE;

const int N = 1e4 + 1;

int pa[N];
std::vector<EDGE> E;

void init() {
  for (int i = 0; i < N; ++i) pa[i] = i;
}

int find(int x) {
  return pa[x] == x ? x : pa[x] = find(pa[x]);
}

void unite(int x, int y) {
  int px = find(x);
  int py = find(y);
  if (px != py) pa[px] = py;
}

bool check(int x, int y) {
  int px = find(x);
  int py = find(y);
  return px == py;
}

int main() {
  int n, e;
  while (std::cin >> n >> e) {
    init();
    for (int i = 0; i < e; ++i) {
      int x, y, c;
      std::cin >> x >> y >> c;
      E.push_back({c, {x, y}});
    }
    std::sort(E.begin(), E.end());
    long long ans = 0;
    for (auto e : E) {
      int c = e.first;
      int n1 = e.second.first;
      int n2 = e.second.second;
      if (!check(n1, n2)) {
        ans += (long long)c;
        unite(n1, n2);
      }
    }
    std::cout << ans << std::endl;
  }
  return 0;
}