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<cstdio>
#include<algorithm>
#include<vector>
#include<iostream>
#include<queue>
#include<stack>
#include<cstring>
#include<string>
#include<map>
#include<set>
#include<sstream>
#include<bitset>
using namespace std;

typedef long long ll;


struct union_find_tree{
	vector<int>data;
	union_find_tree(int n):data(n,-1){}
	bool unite(int x, int y) {
		x = find(x); y = find(y);
		if (x != y) {
			if (data[y] < data[x])swap(x, y);
			data[x] += data[y]; data[y] = x;
		}
		return x != y;
	}
	bool is_same(int x, int y) { return find(x) == find(y); }
	int find(int x) { return data[x] < 0 ? x : data[x] = find(data[x]); }
	int size(int x) { return -data[find(x)]; }
};

int main() {
	int n, m;
	cin >> n >> m;
	vector<tuple<int, int,int>>es;
	for (int i = 0; i < m; i++) {
		int a, b, c;
		cin >> a >> b >> c;
		es.push_back(make_tuple(c, a, b));
	}
	sort(es.begin(), es.end());
	union_find_tree uf(n);
	int ans = 0;

	for (int i = 0; i < m; i++) {
		if (uf.unite(get<1>(es[i]), get<2>(es[i])))ans += get<0>(es[i]);
	}
	cout << ans << endl;
	return 0;
}