1377

#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <string>
#include <math.h>
#include <climits>

//#include <chrono>
//#include <fstream>
//#include <bits/stdc++.h>

#define mp make_pair
#define pb push_back
#define eb emplace_back
#define x first
#define y second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define FOR(i,a,b) for (int i = (a); i < (b); i++)
#define RFOR(i,b,a) for (int i = (b) - 1; i >= (a); i--)

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> veci;
typedef vector<bool> vecb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;

const int INF_I = 1e9;
const ll INF_LL = 1e18;

struct edge {
    int a;
    int b;
    int cost;
};

veci p, sz;
int res = 0;

int find_set(int v) {
    return (v == p[v] ? v : p[v] = find_set(p[v]));
}

void union_set(int a, int b, int w) {
    a = find_set(a);
    b = find_set(b);
    if (a != b) {
        if (sz[a] < sz[b])
            swap(a, b);
        p[b] = a;
        sz[a] += sz[b];
        res += w;
    }
}

int main() {
    /*ifstream cin("in.txt");
    ofstream cout("out.txt");
    auto start_time = chrono::high_resolution_clock::now();*/

    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);


    int n, m;
    cin >> n >> m;
    p.assign(n, 0);
    sz.assign(n, 1);
    sz.assign(n, 0);
    FOR(i, 0, n)p[i] = i;
    vector<edge> vec(m);
    FOR(i, 0, m) {
        cin >> vec[i].a >> vec[i].b >> vec[i].cost;
        vec[i].a--, vec[i].b--;
    }

    sort(all(vec), [](edge a, edge b) {
        return a.cost < b.cost;
    });

    for (edge e : vec)
        union_set(e.a, e.b, e.cost);
    cout << res << "\n";

    /*auto end_time = chrono::high_resolution_clock::now();
    chrono::duration<double> duration = end_time - start_time;
    cout << duration.count() << "\n";
    cin.close();
    cout.close();*/
    return 0;
}