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;

int n, k, m = 0;
int p[10000], r[10000];

struct edge {
	int s, t, w;
};

bool comp(const edge& e1, const edge& e2) {
	return e1.w < e2.w;
}

edge e[100000];

int find(int x) {
	if (p[x] == x)
		return x;
	else
		return p[x] = find(p[x]);
}

void unite(int x, int y) {
	x = find(x);
	y = find(y);

	if (x == y)
		return;

	if (r[x] < r[y])
		p[x] = y;
	else {
		p[y] = x;
		if (r[x] == r[y])
			r[x]++;
	}
}

bool same(int x, int y) {
	return find(x) == find(y);
}

int main()
{
	cin >> n >> k;

	for (int i = 0; i < k; i++)
		cin >> e[i].s >> e[i].t >> e[i].w;

	sort(e, e + k, comp);

	for (int i = 0; i < n; i++) {
		p[i] = i;
		r[i] = 0;
	}

	for (int i = 0; i < k; i++) {
		edge ea = e[i];

		if (!same(ea.s, ea.t)) {
			unite(ea.s, ea.t);
			m += ea.w;
		}
	}

	cout << m << endl;
}