//Bismillahir-Rahmanir-Rahim
#include <bits/stdc++.h>

using namespace std;

#define flash ios_base::sync_with_stdio(0),cin.tie(0)
#define pb push_back
#define ll long long
#define ld long double
#define dbg(x) cerr << #x << " = " << x << "\n";
#define ff first
#define ss second
// #define int long long

/*
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma comment (linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
*/

const long long INF = 1e9 + 7;
const long long MOD = 1e9 + 7;
const int maxn = 1e6 + 10;
const int lg = 20;

int n, p[maxn], m, ans;
vector <pair <int, pair <int, int>> > lst;

int get(int v) {
    if (v == p[v]) {
        return v;
    }
    p[v] = get(p[v]);
    return p[v];
}

void merge(int v, int u) {
    int pv = get(v);
    int pu = get(u);
    if (pv != pu) {
        p[pu] = pv;
    }
}

void press_F_() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        p[i] = i;
    }
    for (int i = 1; i <= m; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        lst.pb({c, {a, b}});
    }
    sort(lst.begin(), lst.end());
    for (int i = 0; i < lst.size(); i++) {
        int a, b, c;
        c = lst[i].ff;
        a = lst[i].ss.ff;
        b = lst[i].ss.ss;
        if (get(a) != get(b)) {
            ans += c;
            // cout << a << " " << b << " " << c << '\n';
            merge(a, b);
        }
    }
    cout << ans;
}

int main() {
    flash;
    int T = 1;
    // cin >> T;
    for (int _ = 1; _ <= T; ++_) {
        // cout << "Case " << i << ": ";
        press_F_();
    }
    return 0;
}