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{
	vector<int> p;
	unionfind(int N): p(vector<int>(N, -1)){
	};
	int root(int x){
		if (p[x] == -1){
			return x;
		} else {
			p[x] = root(p[x]);
			return p[x];
		}
	}
	bool same(int x, int y){
		return root(x) == root(y);
	}
	void unite(int x, int y){
		x = root(x);
		y = root(y);
		if (x != y){
			p[x] = y;
		}
	}
};
long long kruskal(vector<vector<pair<int, int>>> &E){
	int N = E.size();
	vector<tuple<int, int, int>> edges;
	for (int i = 0; i < N; i++){
		for (auto P : E[i]){
			edges.push_back(make_tuple(P.first, i, P.second));
		}
	}
	sort(edges.begin(), edges.end());
	unionfind UF(N);
	long long ans = 0;
	for (auto e : edges){
		int c = get<0>(e);
		int v = get<1>(e);
		int w = get<2>(e);
		if (!UF.same(v, w)){
			UF.unite(v, w);
			ans += c;
		}
	}
	return ans;
}
int main(){
  int v, e;
  cin >> v >> e;
  vector<vector<pair<int, int>>> E(v);
  for (int i = 0; i < e; i++){
    int s, t, w;
    cin >> s >> t >> w;
    E[s].push_back(make_pair(w, t));
  }
  cout << kruskal(E) << endl;
}