#include <iostream>
#include <cstring>
using namespace std;
const int maxn = 105;
int sz[maxn], idx[maxn];
void init() {
    for(int i = 0; i < maxn; i++) {
        idx[i] = i;
        sz[i] = 1;
    }
}

int root(int x) {
    while(x != idx[x]) {
        idx[x] = idx[idx[x]];
        x = idx[x];
    }
    return x;
}

void unite(int A, int B) {
    int rootA = root(A);
    int rootB = root(B);

    if(rootA != rootB) {
        if(sz[rootA] < sz[rootB]) {
            idx[rootA] = idx[rootB];
            sz[rootB] += sz[rootA];
        }
        else {
            idx[rootB] = idx[rootA];
            sz[rootA] += sz[rootB];
        }
    }
}

bool check(int A, int B) {
    return root(A) == root(B);
}


int main() {
    ios_base::sync_with_stdio(false);
    int n, m;
    cin >> n >> m;

    vector<pair<int, pair<int, int>>> graph;

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

        graph.push_back({c, {a, b}});
    }

    sort(graph.begin(), graph.end());

    int mst = 0;
    init();
    for(int i = 0; i < m; i++) {
        int C = graph[i].first;
        int A = graph[i].second.first;
        int B = graph[i].second.second;

        if(!check(A, B)) {
            unite(A, B);
            mst += C;
        }
    }

    cout << mst << endl;
    return 0;
}