#include<bits/stdc++.h>
using namespace std;

//Kruskal
/*
const int NMAX = 200000;
struct ceva
{
    int x,y,z;
}v[NMAX+5];
int t[NMAX+5];
int n,m,s=0;

vector<pair<int,int>>apm;

int cmp(ceva a, ceva b)
{
    return a.z<b.z;
}

int root(int x)
{
    int copie = x;
    while(t[x]>=0)
        x=t[x];
    while(copie!=x)
    {
        int copie2 = t[copie];
        t[copie] = x;
        copie =  copie2;
    }
    return x;
}

void Union(int a, int b)
{
    int r1 = root(a);
    int r2 = root(b);
    if(r1!=r2)
    {
        if(t[r1]<t[r2])
            t[r2]+=t[r1],t[r1]=r2;
        else
            t[r1]+=t[r2],t[r2]=r1;
    }
}

int main()
{
    int i;
    cin>>n>>m;
    for(i=1;i<=m;i++)
        cin>>v[i].x>>v[i].y>>v[i].z;
    sort(v+1,v+m+1,cmp);
    for(i=1;i<=n;i++)
        t[i]=-1;
    for(i=1;i<=m;i++)
    {
        if(root(v[i].x) != root(v[i].y))
        {
            Union(v[i].x,v[i].y);
            apm.push_back({v[i].x,v[i].y});
            s+=v[i].z;
        }
    }
    cout<<s<<'\n'<<apm.size()<<'\n';
    for(auto it:apm)
        cout<<it.first<<" "<<it.second<<'\n';
    return 0;
}*/
    ifstream f("apm.in");
    ofstream g("apm.out");
const int NMAX = 2e5;
const int INF = 1e9;
vector<pair<int, int>> G[NMAX + 1];
int d[NMAX + 1], p[NMAX + 1], vis[NMAX + 1];
int n, m;

void Prim(int nod)
{
    for(int i = 1; i <= n; i++) {
        d[i] = INF;
    }
    d[1] = 0;
    set<pair<int, int>> s;
    s.insert({d[1], 1});
    int apm = 0;
    while(!s.empty()) {
        auto it = s.begin();
        s.erase(it);
        int node = (*it).second;
        int cost = (*it).first;
        if(vis[node]) {
            continue;
        }
        apm += cost;
        vis[node] = 1;
        for(auto it : G[node]) {
            int vecin = it.first;
            int costMuchie = it.second;
            if(!vis[vecin] && d[vecin] > costMuchie) {
                d[vecin] = costMuchie;
                s.insert({d[vecin], vecin});
                p[vecin] = node;
            }
        }
    }
    g << apm << '\n';
    g << n - 1 << '\n';
    for(int i = 2; i <= n; i++) {
        g << i << ' ' << p[i] << '\n';
    }
}

int main()
{
    f >> n >> m;
    for(int i = 1; i <= m; i++) {
        int x, y, c;
        f >> x >> y >> c;
        G[x].push_back({y, c});
        G[y].push_back({x, c});
    }
}