#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream in("apm.in");
ofstream out("apm.out");

const int N=2e5+1;
const int INF=1e5;

int d[N],pred[N],n;
bool in_arb[N];
vector<pair<int,int>> a[N];

int prim()
{
    for(int i=2; i<=n; i++)
    {
        d[i]=INF;
        in_arb[i]=false;
    }
    d[1]=0;
    priority_queue<pair<int,int>> h;
    h.push({0,1});
    int cost=0;
    while(!h.empty())
    {
        int x=h.top().second;
        h.pop();
        if(in_arb[x])
        {
            continue;
        }
        in_arb[x]=true;
        cost+=d[x];
        for(auto p: a[x])
        {
            int y=p.first,c=p.second;
            if(c<d[y])
            {
                d[y]=c;
                pred[y]=x;
                h.push({-c,y});
            }
        }
    }
    return cost;
}

int main()
{
    int m;
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x,y,c;
        in>>x>>y>>c;
        a[x].push_back({y,c});
        a[y].push_back({x,c});
    }
    out<<prim()<<"\n";
    out<<n-1<<"\n";
    for(int i=2; i<=n; i++)
    {
        out<<i<<" "<<pred[i]<<"\n";
    }
    return 0;
}