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<cstdio>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<functional>
#include<map>
#include<cstring>
#define p pair<int,int>
#define P pair<int,p>
using namespace std;

P a[100000];
int Par[10000], Rank[10000];
int saiki(int b) {
	if (Par[b] == b)return b;
	return Par[b]=saiki(Par[b]);
}
void unite(int b, int c) {
	b = saiki(b); c = saiki(c);
	if (Rank[b] > Rank[c]) {
		Par[c] = b;
	}
	else if (Rank[b] < Rank[c]) {
		Par[b] = c;
	}
	else {
		Par[c] = b;
		Rank[b]++;
	}
}
signed main() {
	int b, c; cin >> b >> c;
	for (int d = 0; d < c; d++) {
		int e, f, g; scanf("%d%d%d", &e, &f, &g);
		a[d] = P(g, p(e, f));
	}
	sort(a, a + c);
	int cost = 0;
	for (int i = 0; i < b; i++)Par[i] = i;
	for (P s : a) {
		if (saiki(s.second.first) != saiki(s.second.second)) {
			cost += s.first;
			unite(s.second.first, s.second.second);
		}
	}
	cout << cost << endl;
}