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 <algorithm>
#include <iostream>
#include <vector>

struct Edge {
	int start;
	int target;
	int weight;
};

class UnionFind {
	std::vector<int> m_nodes;

public:
	UnionFind(size_t size) : m_nodes(size) {
		for (size_t i = 0; i < size; i++)
			m_nodes[i] = i;
	}

	int find(int index) {
		int ret = m_nodes[index];
		if (ret == index) return ret;

		ret = find(ret);
		m_nodes[index] = ret;
		return ret;
	}

	void merge(int x, int y) {
		x = find(x);
		y = find(y);
		m_nodes[x] = y;
	}
};

int main()
{
	int v, e;
	std::cin >> v >> e;

	std::vector<Edge> edges;
	edges.reserve(e);

	for (int i = 0; i < e; i++) {
		Edge edge;
		std::cin >> edge.start >> edge.target >> edge.weight;
		edges.push_back(edge);
	}

	std::sort(edges.begin(), edges.end(), [](Edge& x, Edge& y) { return x.weight < y.weight; });

	UnionFind uf(v);
	uint_least64_t weight = 0;

	for (Edge& edge : edges) {
		int s = uf.find(edge.start);
		int t = uf.find(edge.target);

		if (s != t) {
			uf.merge(s, t);
			weight += edge.weight;
		}
	}

	std::cout << weight << std::endl;

	return 0;
}