#include <iostream>
#include <vector>
#include <algorithm>

int main() {
    int N, M, a, b, c, result = 0;
    std::cin >> N >> M;
    std::vector<std::pair<int, std::pair<int, int>>> edges;
    for (int i = 0; i < M; i++) {
        std::cin >> a >> b >> c;
        edges.push_back(std::make_pair(c, std::make_pair(a - 1, b - 1)));
    }
    sort(edges.begin(), edges.end());
    std::vector<int> trees;
    for (int i = 0; i < N; i++) {
        trees.push_back(i);
    }
    for (auto i : edges) {
        if (trees[i.second.first] != trees[i.second.second]) {
            result += i.first;
            int x = trees[i.second.second], y = trees[i.second.first];
            for (int j = 0; j < N; j++) {
                if (trees[j] == x) {
                    trees[j] = y;
                }
            }
        }
    }
    std::cout << result;
}