#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

ifstream cin("apm.in");
ofstream cout("apm.out");

struct muchie{
    int x, y, cost;
};

vector <muchie> muchii;
vector <muchie> apcm;

int n, m, tt[101], sz[101], cost_total;

bool cmp (muchie a, muchie b){
    return a.cost < b.cost;
}

int reprezentant (int x){
    while (x != tt[x])
        x = tt[x];
    return x;
}

bool reunire (int i, int j){
    int ri = reprezentant(i);
    int rj = reprezentant(j);

    if (ri != rj){
        if (sz[ri] < sz[rj]){
            tt[ri] = rj;
            sz[rj] += sz[ri];
        }
        else{
            tt[rj] = ri;
            sz[ri] += sz[rj];
        }
    }
}

int main()
{
    cin>>n>>m;
    for (int i=1;i<=m;i++)
    {
        muchie edge;
        cin>>edge.x>>edge.y>>edge.cost;
        muchii.push_back(edge);
    }

    sort(muchii.begin(), muchii.end(), cmp);

    for (int i=1;i<=n;i++)
        tt[i] = i, sz[i] = 1;

    for (auto edge : muchii)
    {
        int mx = edge.x;
        int my = edge.y;
        if (reprezentant(mx) != reprezentant(my)){
            reunire(mx, my);
            apcm.push_back(edge);
            cost_total += edge.cost;
        }
    }

    cout<<cost_total;
    /*cout<<"Cost total: "<<cost_total<<'\n'<<"Muchiile:\n";
    for (auto edge : apcm)
        cout<<edge.x<<" "<<edge.y<<" "<<edge.cost<<'\n';*/
}

/*
Exemplu input:

9  14
1 3 -11
9 7 3
3 7 4
8 9 4
4 7 5
3 8 5
8 7 5
1 2 10
3 4 10
2 4 11
2 5 11
6 7 11
4 6 12
5 6 13
*/