#include<bits/stdc++.h>
#define ll long long
#define fi first
#define sc second
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
int n, rang[200001], dad[200001], sum, m;
vector<pair<int, int>>ans;
struct muchii
{
    int a, b, cost;
}v[200001];
bool cmp(muchii a, muchii b)
{
    return a.cost<b.cost;
}
int Find(int x)
{
    if(dad[x]==x)
        return x;
    return dad[x]=Find(dad[x]);
}
void Union(int x, int y)
{
    if(rang[x]>rang[y])
        dad[y]=x, rang[x]+=rang[y];
    else
        dad[x]=y, rang[y]+=rang[x];
}
int main()
{
    f>>n>>m;
    for(int i=1; i<=m; i++)
        f>>v[i].a>>v[i].b>>v[i].cost;
    sort(v+1, v+m+1, cmp);
    for(int i=1; i<=n; i++)
    {
        dad[i]=i;
        rang[i]=1;
    }
    for(int i=1; i<=m; i++)
    {
        if(Find(v[i].a)!=Find(v[i].b))
        {
            Union(Find(v[i].a), Find(v[i].b));
            sum+=v[i].cost;
            ans.push_back({v[i].a, v[i].b});
        }
    }
    g<<sum<<'\n';
    g<<ans.size()<<'\n';
    for(int i=0; i<ans.size(); i++)
        g<<ans[i].fi<<' '<<ans[i].sc<<'\n';
    return 0;
}