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;
using namespace std;

#define MAX_V 10000
#define INF 1e9
typedef pair<int, int> pii;

struct edge{
    int to, cost;
};

int V;
bool used[MAX_V];
vector<edge> G[MAX_V];

/*
  O(E log V)
  ?????°??±?????????????????´???vector?????????????????¨???
*/
int prim()
{
    priority_queue<pii, vector<pii>, greater<pii> > Q;
    Q.push(pii(0, 0));
    memset(used, false, sizeof(used));
    int res = 0;
  
    while (!Q.empty()) {
	pii p = Q.top(); Q.pop();
	int v = p.second;
	if (used[v]) continue;
	used[v] = true;
	res += p.first;
	for (int i = 0; i < (int)G[v].size(); i++) {
	    edge e = G[v][i];
	    Q.push(pii(e.cost, e.to));
	}
    }
    return res;
}

int main()
{
    int E,s,t,w;
    cin >> V >> E;
    for (int i = 0; i < E; i++) {
	cin >> s >> t >> w;
	G[s].push_back((edge){t, w});
	G[t].push_back((edge){s, w});
    }
    cout << prim() << endl;
    return 0;
}