#include <bits/stdc++.h>
using namespace std;
int n,m,i,p[200010],s;
pair<int,int>X;
vector<pair<int,int> >ans;
pair<int,pair<int,int> >v[400010];
int Find(int x)
{
    if(x!=p[x])p[x]=Find(p[x]);
    return p[x];
}
void Union(int x,int y)
{
    p[Find(x)]=Find(y);
}
int main()
{
    ifstream f ("apm.in");
    ofstream g ("apm.out");
    f>>n>>m;
    for(i=1; i<=m; ++i)
        f>>v[i].second.first>>v[i].second.second>>v[i].first;
    sort(v+1,v+m+1);
    for(i=1; i<=n; ++i)p[i]=i;
    for(i=1; i<=m; ++i)
        if(Find(v[i].second.first)!=Find(v[i].second.second))
        {
            Union(v[i].second.first,v[i].second.second);
            s+=v[i].first;
            ans.push_back({v[i].second.first,v[i].second.second});
        }
    g<<s<<'\n'<<ans.size()<<'\n';
    while(!ans.empty())
    {
        X=ans.back();
        ans.pop_back();
        g<<X.first<<" "<<X.second<<'\n';
    }
    return 0;
}