/**
 *      purpose : 
 *      author  : kyomukyomupurin
 *      created : 
**/

// input/output
#include <fstream>
#include <iostream>
#include <sstream>
// container class
#include <array>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <vector>
// math, algorithm
#include <algorithm>
#include <cmath>
#include <complex>
#include <numeric>
// etc
#include <bitset>
#include <cassert>
#include <cctype>
#include <cstring>
#include <chrono>
#include <ext/random>
#include <ext/rope>
#include <functional>
#include <iomanip>
#include <random>
#include <utility>
// using-directive
using namespace std;
// alias template
using int64 = long long;
using uint64 = unsigned long long;
using vi = std::vector<int>;
using vl = std::vector<int64>;
using pii = std::pair<int, int>;
using pii = std::pair<int, int>;
using pll = std::pair<int64, int64>;
// text macro replacement
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define all(_) (_).begin(), (_).end()
#define rall(_) (_).rbegin(), (_).rend()
#define print(_) std::cout << (_) << '\n'
#define debug(_) std::cerr << #_ << ": " << (_) << '\n'
// variadic template
template<typename T> inline void chmin(T &a, T b) {if (a > b) a = b; return;}
template<typename T> inline void chmax(T &a, T b) {if (a < b) a = b; return;}
template<typename T> std::ostream& operator<<(std::ostream& os, const std::vector<T>& vec) {
  os << "{";
  for (size_t i = 0; i < vec.size(); ++i) {
    os << vec[i] << ",}"[i == vec.size() - 1];
  }
  return os;
}
template<typename T, typename U> std::ostream& operator<<(std::ostream& os, const std::pair<T, U>& p) {
  return os << "{" << p.first << " " << p.second << "}";
}
// constant
const int INF = (1<<30) - 1;  // 1.073741823e9
const int64 INF64 = (1LL<<62) - 1;  // 4.611686018427387903e18
const int MOD = 1000000007;

class UnionFind {
 public:
  UnionFind(int n) : n_(n) { Initialize(); }
  int GetRoot(int x);
  bool IsSame(int x, int y);
  void Unite(int x, int y);

 private:
  const int n_;
  std::vector<int> parent_;
  std::vector<int> rank_;
  void Initialize();
};

void UnionFind::Initialize() {
  parent_.assign(n_, -1);
  rank_.assign(n_, 0);
}

int UnionFind::GetRoot(int x) {
  if (parent_[x] == -1)
    return x;
  else
    return parent_[x] = GetRoot(parent_[x]);
}

bool UnionFind::IsSame(int x, int y) { return GetRoot(x) == GetRoot(y); }

void UnionFind::Unite(int x, int y) {
  x = GetRoot(x);
  y = GetRoot(y);
  if (x == y) return;
  if (rank_[x] < rank_[y]) std::swap(x, y);
  if (rank_[x] == rank_[y]) ++rank_[x];
  parent_[y] = x;
  return;
}

struct edge{
  int from, to, cost;
};

vector<edge> graph;

int main(){
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(nullptr);

  int V, E; cin >> V >> E;
  for (int i = 0; i < E; ++i) {
    int s, t, w; cin >> s >> t >> w;
    graph.push_back({s, t, w});
  }

  UnionFind uf(V);
  sort(graph.begin(), graph.end(), [](const edge& x, const edge& y){
    return x.cost < y.cost;
  });

  int ans = 0;

  for (auto x : graph) {
    if (!uf.IsSame(x.from, x.to)) {
      uf.Unite(x.from, x.to);
      ans += x.cost;
    }
  }

  cout << ans << '\n';

  return 0;
}


Measured memory_bytes: 4444