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 <stdio.h>
#include <string>
#include <string.h>
#include <algorithm>
#define MAXN 111111
using namespace std;
int pre[MAXN];
int find(int x)
{
	return (pre[x] == x) ? x : pre[x] = find(pre[x]);
}
struct Node
{
	int u, v;
	int power;
}node[MAXN];
bool cmp(const Node& x, const Node& y)
{
	return x.power < y.power;
}
int main(void)
{
	int n, m;

	while (scanf("%d%d", &n, &m) != EOF)
	{
		int ans = 0;

		for (int i = 0; i <= n; i++)pre[i] = i;
		for (int i = 0; i < m; i++)scanf("%d%d%d", &node[i].u, &node[i].v, &node[i].power);
		sort(node, node + m, cmp);
		for (int i = 0; i < m; i++)
		{
			int fx = find(node[i].u);
			int fy = find(node[i].v);

			if (fx != fy)
			{
				ans += node[i].power;
				pre[fx] = fy;
			}
		}
		printf("%d\n", ans);
	}

	return 0;
}