#include<bits/stdc++.h>
// #include<atcoder/all>
// #include<boost/multiprecision/cpp_int.hpp>

using namespace std;
// using namespace atcoder;
// using bint = boost::multiprecision::cpp_int;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<ll>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using ve = vector<vector<int>>;
using vb = vector<bool>;
using vvb = vector<vb>;
#define rep(i,s,n) for(ll i = (ll)s;i < (ll)n;i++)
#define rrep(i,l,r) for(ll i = r-1;i >= l;i--)
#define ALL(x) (x).begin(),(x).end()
#define sz(c) ((ll)(c).size())
#define LB(A,x) (int)(lower_bound(A.begin(),A.end(),x)-A.begin())
#define UB(A,x) (int)(upper_bound(A.begin(),A.end(),x)-A.begin())
// #define MOD 1000000007
#define MOD 998244353
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<typename T>ostream&operator<<(ostream&os,vector<T>&v){for(int i = 0;i < v.size();i++)os<<v[i]<<(i+1!=v.size()?" ":"");return os;}
template<typename T>istream&operator>>(istream&is,vector<T>&v){for(T&in:v)is>>in;return is;}
template<typename T1,typename T2>ostream&operator<<(ostream&os,pair<T1,T2>&p){os<<p.first<<" "<<p.second;return os;}
template<typename T1,typename T2>istream&operator>>(istream&is,pair<T1,T2>&p){is>>p.first>>p.second;return is;}
template<typename T> inline bool chmax(T &a,T b){if(a < b){a = b;return true;}return false;}
template<typename T> inline bool chmin(T &a,T b){if(a > b){a = b;return true;}return false;}
ld dist(ld x1,ld y1,ld x2, ld y2){return sqrtl((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));}


class UnionFind{
  public:
  vector<int> par;
  UnionFind(long long size) : par(size,-1){}
  bool unite(int x,int y){
    x = root(x),y = root(y);
    if(x == y)return false;
    if(par[y] < par[x])swap(x,y);
    par[x] += par[y];
    par[y] = x;
    return true;
  }
  bool find(int x,int y){
    return root(x) == root(y);
  }
  int root(int x){
    return par[x] < 0 ? x : par[x] = root(par[x]);
  }
  int size(int x){
    return -par[root(x)];
  }
};

int main(){
  
  ios_base::sync_with_stdio(0), cin.tie(0);
  int n,m;cin >> n >> m;
  UnionFind uf(n);
  vector<tuple<ll,int,int>> v(m);
  rep(i,0,m){
    auto &[c,a,b] = v[i];cin >> a >> b >> c;
    a--;b--;
  }
  sort(ALL(v),greater<tuple<ll,int,int>>());
  ll res = 0;
  rep(i,0,m){
    auto [c,a,b] = v[i];
    if(uf.unite(a,b))res += 2*c;
  }
  cout << res << endl;
  

  return 0;
}