#include<iostream>
#include<cstring>
#include<algorithm>
#include<vector>
#include<cassert>
#include<map>
using namespace std;
#define int long long

struct UnionFind
{
	private:
	int n;
	vector<int> par,siz;

	public:
	UnionFind(int n) :n(n),par(n,-1),siz(n,1) {}

	int root(int u)
	{
		assert(0 <= u && u < n);
		return (par[u] < 0 ? u:par[u] = root(par[u]));
	}

	bool same(int u,int v)
	{
		assert(0 <= u && u < n && 0 <= v && v < n);
		return root(u) == root(v);
	}

	bool unite(int u,int v)
	{
		assert(0 <= u && u < n && 0 <= v && v < n);
		u = root(u),v = root(v);
		if(u == v) return false;

		if(siz[u] < siz[v]) swap(u,v);

		siz[u] += siz[v];
		par[v] = u;

		return true;
	}

	int size(int u)
	{
		assert(0 <= u && u < n);
		return siz[root(u)];
	}

	vector<vector<int>> components()
	{
		vector<vector<int>> ret(n);
		for(int u = 0;u < n;u++) ret[root(u)].push_back(u);

		ret.erase(remove_if(ret.begin(),ret.end(),[](vector<int> v) { return v.empty();}),ret.end());

		return ret;
	}
};

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.same(e[i].u, e[i].v)){
            ans += e[i].c * dsu.size(e[i].u) * dsu.size(e[i].v);
            dsu.unite(e[i].u, e[i].v);
        }
    }
    cout << ans << '\n';
}

signed main(){
    ios::sync_with_stdio(false);
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    int t = 1;
    //cin >> t;
    while(t--){
        solve();
    }
    return 0;
}