/*
 ID: bradyawn
 PROG: cf
 LANG: C++11
 */

#include <iostream>
#include <algorithm>
#include <iomanip>
#include <fstream>
#include <vector>
#include <string>
#include <cmath>
#include <map>
#include <utility>
#include <algorithm>
#include <set>
#include <ctime>
#include <queue>
#include <stack>

#define ll long long


//#define inf cin
//#define outf cout

using namespace std;

int main()
{
    //ifstream inf("");
    //fstream outf("");
    //cout << setprecision(10);

    ll n, m;
    cin >> n >> m;

    vector<vector<ll>> graph(n, vector<ll>());

    vector<vector<ll>> prim(n, vector<ll>(n));

    for (int i = 0; i < m; i++)
    {
        int a, b, c;
        cin >> a >> b >> c;

        a--; b--;

        graph[a].push_back(b);
        graph[b].push_back(a);

        prim[a][b] = c;
        prim[b][a] = c;


    }

    vector<ll> nodes;
    vector<bool> vis(n);
    nodes.push_back(0);
    vis[0] = true;
    ll ret = 0;

    while (nodes.size() < n) //when amnt nodes reaches total nodes, mst found
    {
        ll toVis = -1;
        ll len = 1000001;
        for (auto e : nodes) //loop possible start nodes
        {
            for (auto u : graph[e]) //vis nodes adj to start
            {
                if (!vis[u]) //if not vis
                {
                    if (prim[e][u] < len)
                    {
                        len = prim[e][u];
                        toVis = u;
                    }
                }
            }
        }

        ret += len;
        vis[toVis] = true;
        nodes.push_back(toVis);

    }

    cout << ret << endl;

    return 0;

}