#include<iostream>
#include<cstring>
#include<algorithm>
#include<vector>
#include<numeric>
#include<map>
using namespace std;
const int N = 1e5 + 5;

class UnionFind{

    public:
    std::vector<int> par;
    std::vector<int> rank;
    std::vector<int> sz;
    std::vector<int> root;

    UnionFind(int size){
        rank=std::vector<int>(size+1,0);
        
        par = std::vector<int>(size+1,0);
        std::iota(par.begin(),par.end(),0);//#include<numeric>
        sz = std::vector<int>(size+1,1);
        root=std::vector<int>(size+1);
        std::iota(root.begin(),root.end(),0);
    }  

    

    ~UnionFind(){
        std::vector<int>().swap(rank);
        std::vector<int>().swap(par);
        std::vector<int>().swap(sz);
        std::vector<int>().swap(root);
    }  


    int find(int x){
        if(par[x]==x)return x;
        else return par[x] = find(par[x]);
    }

    bool issame(int u,int v){
        return find(u)==find(v);
    }


    void merge(int u,int v){
        u = find(u);
        v = find(v);
        if(u==v) return;

       
        if(rank[u]<rank[v]) std::swap(u,v);
        
        par[v]=u;
        sz[u]+=sz[v];
        if(rank[u]==rank[v])rank[u]++;

    }
    

    int size(int u){
        u=find(u);
        return sz[u];
    }

    std::map<int,std::vector<int>> element(){
        std::map<int,std::vector<int>> mp;
        for(int i=0;i<par.size();i++){
            root[i]=find(i);
            mp[root[i]].push_back(i);
        }
        return mp;

    }
};

struct edge{
    int u, v, c;
};
bool cmp(edge a, edge b){
    return a.c < b.c;
}

void solve(){
    int n, m;
    cin >> n >> m;
    vector<edge>e;
    for(int i = 1; i <= m; i++){
        int u, v, c;
        cin >> u >> v >> c;
        u--, v--;
        e.push_back({u, v, c});
    }
    sort(e.begin(), e.end(), cmp);
    UnionFind dsu(n);
    long long ans = 0;
    for(int i = 0; i < m; i++){
        if(!dsu.issame(e[i].u, e[i].v)){
            ans += e[i].c * dsu.size(e[i].u) * dsu.size(e[i].v);
            dsu.merge(e[i].u, e[i].v);
        }
    }
    cout << ans << '\n';
}

int main(){
    int t = 1;
    //cin >> t;
    while(t--){
        solve();
    }
    return 0;
}