#include <bits/stdc++.h>
using namespace std;
using lint = long long;
const lint mod = 1e9 + 7;
#define all(x) (x).begin(), (x).end()
#define bitcount(n) __builtin_popcountl((lint)(n))
#define fcout cout << fixed << setprecision(15)
#define highest(x) (63 - __builtin_clzl(x))
#define rep(i, n) for(int i = 0; i < n; i++)
const int inf9 = 1e9; const lint inf18 = 1e18;
template<class T> inline void YES(T condition){ if(condition) cout << "YES" << endl; else cout << "NO" << endl; }
template<class T> inline void Yes(T condition){ if(condition) cout << "Yes" << endl; else cout << "No" << endl; }
template<class T = string, class U = char>int character_count(T text, U character){ int ans = 0; for(U i: text){ ans += (i == character); } return ans; }
lint power(lint base, lint exponent, lint module){ if(exponent % 2){ return power(base, exponent - 1, module) * base % module; }else if(exponent){ lint root_ans = power(base, exponent / 2, module); return root_ans * root_ans % module; }else{ return 1; }}
struct position{ int y, x; }; position mv[4] = {{0, -1}, {1, 0}, {0, 1}, {-1, 0}}; // double euclidean(position first, position second){ return sqrt((second.x - first.x) * (second.x - first.x) + (second.y - first.y) * (second.y - first.y)); }
template<class T, class U> string to_string(pair<T, U> x){ return to_string(x.first) + "," + to_string(x.second); } string to_string(string x){ return x; }
template<class itr> void array_output(itr start, itr goal){ string ans; for(auto i = start; i != goal; i++) ans += to_string(*i) + " "; if(!ans.empty()) ans.pop_back(); cout << ans << endl; }
template<class itr> void cins(itr first, itr last){ for(auto i = first; i != last; i++){ cin >> (*i); } }
template<class T> T gcd(T a, T b){ if(a && b){ return gcd(min(a, b), max(a, b) % min(a, b)); }else{ return a; }} template<class T> T lcm(T a, T b){ return a / gcd(a, b) * b; }
struct combination{ vector<lint> fact, inv; combination(int sz) : fact(sz + 1), inv(sz + 1){ fact[0] = 1; for(int i = 1; i <= sz; i++){ fact[i] = fact[i - 1] * i % mod; } inv[sz] = power(fact[sz], mod - 2, mod); for(int i = sz - 1; i >= 0; i--){ inv[i] = inv[i + 1] * (i + 1) % mod; } } lint P(int n, int r){ if(r < 0 || n < r) return 0; return (fact[n] * inv[n - r] % mod); } lint C(int p, int q){ if(q < 0 || p < q) return 0; return (fact[p] * inv[q] % mod * inv[p - q] % mod); } };
template<class itr> bool next_sequence(itr first, itr last, int max_bound){ itr now = last; while(now != first){ now--; (*now)++; if((*now) == max_bound){ (*now) = 0; }else{ return true; } } return false; }
template<class itr, class itr2> bool next_sequence2(itr first, itr last, itr2 first2, itr2 last2){ itr now = last; itr2 now2 = last2; while(now != first){ now--, now2--; (*now)++; if((*now) == (*now2)){ (*now) = 0; }else{ return true; } } return false; }
int at(lint i, int j){ return (i >> j) & 1; }

struct union_find{
    vector<int> par, size;
    
    union_find(int sz){
        par.resize(sz, -1);
        size.resize(sz, 1);
    }
    
    int find(int a){
        if(par[a] == -1){
            return a;
        }
        return par[a] = find(par[a]);
    }
    
    void unite(int a, int b){
        int root_a = find(a), root_b = find(b);
        if(root_a == root_b){
            return;
        }
        if(size[root_a] < size[root_b]){
            swap(a, b);
            swap(root_a, root_b);
        }
        par[root_b] = root_a;
        size[root_a] += size[root_b];
    }
    
    bool is_group(int a, int b){
        return find(a) == find(b);
    }
};

struct road{
    int now;
    lint cost;
};

int sz;
vector<vector<road>> roads;

lint MST(){
    vector<pair<lint, pair<int, int>>> sorted_roads;
    for(int i = 0; i < sz; i++){
        for(road j: roads[i]){
            sorted_roads.push_back({j.cost, {i, j.now}});
        }
    }
    sort(all(sorted_roads));
    union_find uf(sz);
    lint ans = 0;
    int cnt = 0;
    for(int i = 0; i < sorted_roads.size(); i++){
        auto look = sorted_roads[i];
        int a = look.second.first, b = look.second.second;
        if(uf.is_group(a, b)){
            continue;
        }
        ans += look.first;
        uf.unite(a, b);
        cnt++;
    }
    return ans;
}

int main(){
    int N, M;
    cin >> N >> M;
    roads.resize(N);
    for(int i = 0; i < M; i++){
        int s, t;
        lint w;
        cin >> s >> t >> w;
        roads[s].push_back({t, w});
        roads[t].push_back({s, w});
    }
    sz = N;
    cout << MST() << endl;
}




Measured memory_bytes: 12392