/* 💕💕💕💕💕
💗💗💗💗💗
  /)/)
( . .)
( づ💗

    💗💗💗  💗💗💗
  💗💗💗💗💗💗💗💗💗
  💗💗💗💗💗💗💗💗💗
    💗💗💗💗💗💗💗
      💗💗💗💗💗
        💗💗💗
          💗

*/

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <cstdint>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <vector>
template <int mod>
struct ModInt {
  int x;
  ModInt() : x(0) {}
  ModInt(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
  ModInt &operator+=(const ModInt &p) {
    if ((x += p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator-=(const ModInt &p) {
    if ((x += mod - p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator*=(const ModInt &p) {
    x = (int)(1LL * x * p.x % mod);
    return *this;
  }
  ModInt &operator/=(const ModInt &p) {
    *this *= p.inverse();
    return *this;
  }
  ModInt &operator^=(long long p) {  // quick_pow here:3
    ModInt res = 1;
    for (; p; p >>= 1) {
      if (p & 1) res *= *this;
      *this *= *this;
    }
    return *this = res;
  }
  ModInt operator-() const { return ModInt(-x); }
  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
  ModInt operator^(long long p) const { return ModInt(*this) ^= p; }
  bool operator==(const ModInt &p) const { return x == p.x; }
  bool operator!=(const ModInt &p) const { return x != p.x; }
  explicit operator int() const { return x; }  // added by QCFium
  ModInt operator=(const int p) {
    x = p;
    return ModInt(*this);
  }  // added by QCFium
  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while (b > 0) {
      t = a / b;
      a -= t * b;
      std::swap(a, b);
      u -= t * v;
      std::swap(u, v);
    }
    return ModInt(u);
  }
  friend std::ostream &operator<<(std::ostream &os, const ModInt<mod> &p) {
    return os << p.x;
  }
  friend std::istream &operator>>(std::istream &is, ModInt<mod> &a) {
    long long x;
    is >> x;
    a = ModInt<mod>(x);
    return (is);
  }
};
using mint = ModInt<1000000007>;
const int MOD = 1000000007;
struct MComb {
  std::vector<mint> fact;
  std::vector<mint> inversed;
  MComb(int n) {  // O(n+log(mod))
    fact = std::vector<mint>(n + 1, 1);
    for (int i = 1; i <= n; i++) fact[i] = fact[i - 1] * mint(i);
    inversed = std::vector<mint>(n + 1);
    inversed[n] = fact[n] ^ (MOD - 2);
    for (int i = n - 1; i >= 0; i--)
      inversed[i] = inversed[i + 1] * mint(i + 1);
  }
  mint ncr(int n, int r) {
    if (n < r) return 0;
    return (fact[n] * inversed[r] * inversed[n - r]);
  }
  mint npr(int n, int r) { return (fact[n] * inversed[n - r]); }
  mint nhr(int n, int r) {
    assert(n + r - 1 < (int)fact.size());
    return ncr(n + r - 1, r);
  }
};

mint ncr(int n, int r) {
  mint res = 1;
  for (int i = n - r + 1; i <= n; i++) res *= i;
  for (int i = 1; i <= r; i++) res /= i;
  return res;
}

/*
mint res = (mint(2) ^ n) - 1 - ncr(n, a) - ncr(n, b);
std::cout << res << std::endl;
*/

template <typename T>
struct DSU {
  std::vector<T> f, siz;
  DSU(int n) : f(n), siz(n, 1) { std::iota(f.begin(), f.end(), 0); }
  T leader(T x) {
    while (x != f[x]) x = f[x] = f[f[x]];
    return x;
  }
  bool same(T x, T y) { return leader(x) == leader(y); }
  bool merge(T x, T y) {
    x = leader(x);
    y = leader(y);
    if (x == y) return false;
    siz[x] += siz[y];
    f[y] = x;
    return true;
  }
  T size(int x) { return siz[leader(x)]; }
};
void solve() {
  int n, m;
  std::cin >> n >> m;

  DSU<int> dsu(n);
  std::vector<std::tuple<long long, int, int>> edges(m);

  for (int i = 0; i < m; i++) {
    int u, v;
    long long w;
    std::cin >> u >> v >> w;
    u--, v--;
    edges[i] = {w, u, v};
  }
  long long ans = 0;
  std::sort(edges.begin(), edges.end());
  for (auto [w, u, v] : edges) {
    if (dsu.same(u, v)) continue;

    ans += w * dsu.size(u) * dsu.size(v);
    dsu.merge(u, v);
  }
  std::cout << ans << '\n';
}

int main() {
  int t = 1;
  // std::cout << std::boolalpha;
  // std::cin >> t;

  while (t--) solve();
  return 0;
}