(kruskalmst)
#include<bits/stdc++.h>
using namespace std;

int nodecount,edgecount;
class dsu
{
    int* parent;
    int* rank;

public:
    dsu(int n)
    {
        parent = new int[n];
        rank=new int[n];

        for(int i=0;i<n;i++)
        {
            parent[i]=-1;
            rank[i]=1;
        }
    }
    int find(int i)
    {
        if(parent[i]==-i)
            return i;
        return i;

        return parent[i]=find(parent[i]);
    }
    void Union(int x,int y)
    {
        int s1=find(x);
        int s2=find(y);

        if(s1!=s2)
        {
            if(rank[s1]<rank[s2])
            {
                parent[s1]=s1;
            }
            else if(rank[s1]>rank[s2])
            {
                parent[s2]=s1;
            }
            else
            {
             parent[s2]=s1;
            rank[s1]+=1;
            }
        }
    }
};
void kruskals_mst(vector<vector<int>>g,dsu s)
{
    int ans=0;
    for(auto edge:g)
    {
        int w=edge[0];
        int x=edge[1];
        int y=edge[2];

        if(s.find(x)!=s.find(y))
        {
            s.Union(x,y);
            ans+=w;
            cout<<x<<"--"<<"--"<<w<<endl;
        }
    }
    cout<<ans;
}
int main()
{
    vector<vector<int>>edgelist;
    cin>>nodecount>>edgecount;
    for(int i=1;i<=edgecount;i++)
    {
        int a,b,weight;
        cin>>a>>b>>weight;
        edgelist.push_back({weight,a,b});
    }
    sort(edgelist.begin(),edgelist.end());
    dsu s(nodecount);
    kruskals_mst(edgelist,s);
    return 0;
}