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 <algorithm>

const int N = 10001, E = 100001;

struct Edge{
	int u, v, cost;
	bool operator<(const Edge& e) const {
		return cost < e.cost;
	}
};

int rank[N], par[N];
Edge edge[E];
int n, e;

void init(int n){
	for(int i = 0; i < n; ++i){
		par[i] = i;
		rank[i] = 0;
	}
}

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

void unite(int x, int y){
	x = find(x);
	y = find(y);
	if(x == y) return;
	
	if(rank[x] < rank[y]){
		par[x] = y;
	}else{
		par[y] = x;
		if(rank[x] == rank[y])++rank[x];
	}
}

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

long long kruskal(){
	std::sort(edge, edge + e);
	init(n);
	long long res = 0;
	for(int i = 0; i < e; ++i){
		if(!same(edge[i].u, edge[i].v)){
			unite(edge[i].u, edge[i].v);
			res += edge[i].cost;
		}
	}
	return res;
}
	
int main(){
	std::cin >> n >> e;
	
	for(int i = 0; i < e; ++i){
		int a, b, c;
		std::cin >> a >> b >> c;
		edge[i] = {a, b, c};
	}
	
	std::cout << kruskal() << std::endl;

	return 0;
}