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 i64 = int64_t;

struct edge {
    int a, b;
    i64 w;
};

i64 kruskal(vector<edge>& edges, int n) {
    vector<int> par(n);
    for (int i = 0; i < n; i++) {
        par[i] = i;
    }
    function<int(int)> find = [&](int x) {
        if (x == par[x]) return x;
        return par[x] = find(par[x]);
    };
    auto unite = [&](int x, int y) {
        x = find(x);
        y = find(y);
        par[x] = y;
    };
    auto same = [&](int x, int y) {
        return find(x) == find(y);
    };
    sort(edges.begin(), edges.end(), [](edge a, edge b) {
        return a.w < b.w;
    });
    i64 ret = 0;
    for (edge e: edges) {
        if (!same(e.a, e.b)) {
            unite(e.a, e.b);
            ret += e.w;
        }
    }
    return ret;
}

int main() {
    int v, e;
    cin >> v >> e;
    vector<edge> edges;
    for (int i = 0; i < e; i++) {
        int a, b;
        i64 w;
        cin >> a >> b >> w;
        edges.push_back({a, b, w});
    }
    cout << kruskal(edges, v) << endl;
}