#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto& i:a)
#define ff first 
#define ss second 
#define all(a) begin(a),end(a)
#define allr(a) rbegin(a),rend(a)
#define pb push_back
using namespace std;
using ll =long long;
using pii=pair<int,int>;
using pll=pair<ll,ll>;
using vi=vector<int>;
using vll=vector<ll>;
template<class T> inline bool chmin(T& a,T b){return a>b?a=b,1:0;}
template<class T> inline bool chmax(T& a,T b){return a<b?a=b,1:0;}

int n,m;
struct Edge{
    int to,from;ll cost;
};
bool compare(Edge a,Edge b){
    return a.cost>b.cost;
};
vector<int> par;
int find(int x){return par[x]<0?x:par[x]=find(par[x]);}
int same(int x,int y){return find(x)==find(y);}
int merge(int x,int y){
    x=find(x),y=find(y);
    if(same(x,y))return false;
    if(par[x]>par[y])swap(x,y);
    par[x]+=par[y];
    par[y]=x;
    return true;
}
template<class T> inline int ub(vector<T> &v,T c){return distance(begin(v),upper_bound(all(v),c));}
int main(){
    //cin.tie(0)->sync_with_stdio(0);
    cin>>n>>m;
    par.resize(n,-1);
    vector<Edge> e;
    rep(i,0,m){
        int a,b,c;cin>>a>>b>>c;a--;b--;
        e.pb(Edge{a,b,c});
    }
    sort(all(e),compare);
    ll ans{};
    rep(i,0,m){
        int u=e[i].to,v=e[i].from;ll cost=e[i].cost;
        if(same(u,v))continue;
        merge(u,v);
        ans+=cost*2;
    }
    cout<<ans<<endl;
    return 0;
}
/*
全域木を構築する。木上の各辺は必ず二回通る
MST
*/