#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 998244353;
// constexpr int MOD = 1000000007;
constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1};
constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U>
inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

template <typename CostType>
struct Edge {
  int src, dst;
  CostType cost;
  explicit Edge(const int src, const int dst, const CostType cost = 0)
      : src(src), dst(dst), cost(cost) {}
  inline bool operator<(const Edge& x) const {
    if (cost != x.cost) return cost < x.cost;
    return src != x.src ? src < x.src : dst < x.dst;
  }
  inline bool operator<=(const Edge& x) const { return !(x < *this); }
  inline bool operator>(const Edge& x) const { return x < *this; }
  inline bool operator>=(const Edge& x) const { return !(*this < x); }
};

struct UnionFind {
  explicit UnionFind(const int n) : data(n, -1) {}

  int root(const int ver) {
    return data[ver] < 0 ? ver : data[ver] = root(data[ver]);
  }

  bool unite(int u, int v) {
    u = root(u);
    v = root(v);
    if (u == v) return false;
    if (data[u] > data[v]) std::swap(u, v);
    data[u] += data[v];
    data[v] = u;
    return true;
  }

  bool is_same(const int u, const int v) { return root(u) == root(v); }

  int size(const int ver) { return -data[root(ver)]; }

 private:
  std::vector<int> data;
};

int main() {
  int n, m; cin >> n >> m;
  vector<Edge<int>> edges;
  edges.reserve(m);
  REP(_, m) {
    int a, b, w; cin >> a >> b >> w; --a; --b;
    edges.emplace_back(a, b, w);
  }
  sort(ALL(edges));
  UnionFind union_find(n);
  ll ans = 0;
  for (const auto [a, b, w] : edges) {
    if (!union_find.is_same(a, b)) {
      ans += 1LL * union_find.size(a) * union_find.size(b) * w;
      union_find.unite(a, b);
    }
  }
  cout << ans << '\n';
  return 0;
}