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 <vector>
#include <algorithm>
#include <queue>
using namespace std;

typedef long long ll;
int p[20000];
int r[20000];

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

int find(int i){
    if(p[i]==i)return i;
    return p[i] = find(p[i]);
}
void unite(int a,int b){
    int x = find(a);
    int y = find(b);
    if(x==y)return ;
    if(r[x]<r[y]){
        p[x] = y;
        
    }else{
        p[y] = x;
        if(r[x]==r[y])r[x]++;
    }
}

int main(){
    int n,m;
    cin >> n >> m;
    vector<pair<ll,pair<int,int> > > g;
    for(int i=0;i<m;i++){
        int s,t;
        ll d;
        cin >> s >> t >> d;
        g.push_back(make_pair(d,make_pair(s,t)));
    }
    sort(g.begin(),g.end());
    init(n);
    ll ans = 0;
    for(int i=0;i<m;i++){
        int s,t;
        s = g[i].second.first;
        t = g[i].second.second;
        if(find(s)!=find(t)){
            ans += g[i].first;
            unite(s,t);
        }
    }
    cout << ans << endl;
    return 0;
}