#include <bits/stdc++.h>

using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
const int N=2e5+10,INF=1e7+10;
vector <pair<int,int>> a[N];
priority_queue<pair<int,int>> pq;
int n,cost,pred[N],dist[N];
bool viz[N];
int main()
{
    int m;
    f>>n>>m;
    for(int i=1;i<=n;i++)
    {
        dist[i]=INF;
    }
    dist[1]=0;
    for(int i=1;i<=m;i++)
    {
        int x,y,z;
        f>>x>>y>>z;
        a[x].push_back({y,z});
        a[y].push_back({x,z});
    }
    pq.push({0,1});
    while(!pq.empty())
    {
        int x=pq.top().second;
        pq.pop();
        if(viz[x])
        continue;
        viz[x]=1;
        for(auto i:a[x])
        {
            int y=i.first;
            int c=i.second;
            if(c<dist[y] && !viz[y])
            {
                dist[y]=c;
                pred[y]=x;
                pq.push({-c,y});
            }
        }
    }
    for(int i=1;i<=n;i++)
    {
        cost+=dist[i];
    }
    g<<cost<<"\n"<<n-1<<"\n";
    for(int i=2;i<=n;i++)
    {
        g<<i<<" "<<pred[i]<<"\n";
    }
    return 0;
}