#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define all(x) x.begin(),x.end()
#define rep(i,a,b) for(int i=a;i<=b;i++)
#define rep_r(i,a,b) for(int i=a;i>=b;i--)
#define each(a,x) for (auto& x : a)
using pi = pair<int,int>;
using pl = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
#define sz(x) int(x.size())
#define so(x) sort(all(x))
#define so_r(x) sort(all(x),greater<int>())
#define lb lower_bound
#define ub upper_bound
const char nl = '\n';
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,1,-1};
int bit_cnt(int x){
    return __builtin_popcount(x);
}
ll bex(ll a, ll b, ll mod = 1e9 + 7){ll res = 1LL; while(b){ if (b&1) res = res * a % mod; a = a * a % mod; b >>= 1;} return res;}
template<class t,class u> bool chmax(t&a,u b){if(a<b){a=b;return true;}else return false;}
template<class t,class u> bool chmin(t&a,u b){if(b<a){a=b;return true;}else return false;}

const int MOD = 998244353;
const int N = 1e5 + 5;
const ll INF = 1e16;
int n,m; 
vector<vl> edges;
// https://yukicoder.me/problems/no/2200
// De bai: Cho do thi vo huong co trong so co N dinh va M canh 
// Cost de di tu u -> v = min of (max_edge in path) for path in all_paths from u -> v

// Solve: Su dung kruskal tim MST
// Trong bai nay ta chi quan tam toi cac canh thuoc MST, cac canh khong thuoc MST ta ignore
// why? : gia su path (1,3) tren MST = 1 -> 2 -> 3 trong do 1 -> 2 = 4 va 2 -> 3 = 5
// => 1 -> 3 >= 5 vi neu no nho hon 5 thi da co the noi thang tu 1 -> 3 roi 

vector<int> fa, sz; 
int find(int u) {return (u == fa[u] ? u : fa[u] = find(fa[u]));}
bool same(int u, int v){
    u = find(u);
    v = find(v); 
    return u == v;
}
void merge(int u, int v){ 
    u = find(u);
    v = find(v);
    if (u == v) return;
    if (sz[u] < sz[v]) swap(u,v);
    sz[u] += sz[v]; 
    fa[v] = u;
}
void solve(){
    cin >> n >> m;
    fa.resize(n+1);
    sz.resize(n+1); 
    rep(i,1,n) fa[i] = i, sz[i] = 1;
    rep(i,1,m){
        int u,v; ll w; cin >> u >> v >> w;
        edges.push_back({w,u,v});
    } 
    sort(all(edges));
    ll ans = 0;
    each(edges,ed){
        ll w = ed[0];
        int u = ed[1], v = ed[2]; 
        if (same(u,v)) continue;
        ans += w * sz[find(u)] * sz[find(v)];
        merge(u,v);
    }
    cout << ans << nl;
}

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

    int t = 1; 
    // cin >> t;

    while (t--){
        solve();
    }
}