#include <bits/stdc++.h>
using namespace std;
using ll = long long;

struct UnionFind {
private:
  int n_;
  std::vector<int> parent_or_size_;
  int group_count_;
  
public:
  explicit UnionFind(int n) : n_(n), parent_or_size_(n, -1), group_count_(n) {}
  
  bool merge(int u, int v) {
    assert(0 <= u && u < n_);
    assert(0 <= v && v < n_);
    
    u = root_internal(u);
    v = root_internal(v);
    if (u == v) {
      return false;
    }
    
    if (parent_or_size_[u] > parent_or_size_[v]) {
      std::swap(u, v);
    }
    
    parent_or_size_[u] += parent_or_size_[v];
    parent_or_size_[v] = u;
    --group_count_;
    
    return true;
  }
  
  bool same(int u, int v) {
    assert(0 <= u && u < n_);
    assert(0 <= v && v < n_);
    return root_internal(u) == root_internal(v);
  }
  
  int root(int v) {
    assert(0 <= v && v < n_);
    return root_internal(v);
  }
  
  int size(int v) {
    assert(0 <= v && v < n_);
    return -parent_or_size_[root_internal(v)];
  }
  
  int group_count() const {
    return group_count_;
  }
  
  std::vector<std::vector<int>> groups() {
    std::vector<int> root_buf(n_);
    std::vector<int> group_id(n_, -1);
    
    std::vector<std::vector<int>> result;
    result.reserve(group_count_);
    
    for (int i = 0; i < n_; ++i) {
      root_buf[i] = root_internal(i);
    }
    
    for (int i = 0; i < n_; ++i) {
      if (parent_or_size_[i] < 0) {
        group_id[i] = (int)result.size();
        result.emplace_back();
        result.back().reserve(-parent_or_size_[i]);
      }
    }
    
    for (int i = 0; i < n_; ++i) {
      result[group_id[root_buf[i]]].push_back(i);
    }
    
    return result;
  }
  
private:
  int root_internal(int v) {
    if (parent_or_size_[v] < 0) {
      return v;
    }
    return parent_or_size_[v] = root_internal(parent_or_size_[v]);
  }
};

int main() {
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);
  
  int N, M;
  cin >> N >> M;
  vector<pair<int, pair<int, int>>> E(M);
  for (int i = 0; i < M; i++) {
    cin >> E[i].second.first >> E[i].second.second >> E[i].first;
    E[i].second.first--;
    E[i].second.second--;
  }
  
  sort(E.begin(), E.end());
  
  UnionFind uf(N);
  ll ans = 0;
  for (int i = 0; i < M; i++) {
    if (!uf.same(E[i].second.first, E[i].second.second)) {
      ans += (ll)E[i].first * uf.size(E[i].second.first) * uf.size(E[i].second.second);
      uf.merge(E[i].second.first, E[i].second.second);
    }
  }
  
  cout << ans << '\n';
}