#include <iostream>
#include <fstream>
#define nmax 200001
#define inf 1e9
#include <vector>
#include <queue>
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
vector<pair<int,int> > v[nmax];
int n,m,a,b,c,nod,p,cost;
class CustomCompare
{
public:
    bool operator()(pair<int,pair<int,int> > n1,pair<int,pair<int,int> > n2) {
        return n1.second.second>n2.second.second;
    }
};
struct haide
{
    int a,b;
}t[200005];
priority_queue<pair<int,int>,vector<pair<int,pair<int,int> > >, CustomCompare >h;

bool abi[nmax];
int main()
{
    int i;

    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>a>>b>>c;
        v[a].push_back(make_pair(b,c));
            v[b].push_back(make_pair(a,c));


    }

    abi[1]=1;
    for(int i=0;i<v[1].size();i++)
        h.push(make_pair(1,make_pair(v[1][i].first,v[1][i].second)));
        int nr=1;
    while(nr<n)
    {nr++;
while(abi[h.top().second.first]==1) h.pop();
    int nod=h.top().second.first;
abi[nod]=1;
    t[++p].a=h.top().first;
    t[p].b=nod;
    cost+=h.top().second.second;
    h.pop();
    for(int i=0;i<v[nod].size();i++)
      if(abi[v[nod][i].first]==0)  {h.push(make_pair(nod,make_pair(v[nod][i].first,v[nod][i].second)));abi[v[nod][i].first]==1;};


    }
    g<<cost<<endl;
    g<<p<<endl;
    for(int i=1;i<=p;i++)
        g<<t[i].a<<" "<<t[i].b<<endl;

    return 0;
}