#include <vector>
#include <fstream>
#include <cstdlib>

using namespace std;
typedef pair<int, int> pr;
const int N_MAX=100011;
const int oo=1<<29;

vector<pr> G[N_MAX];
vector<pr>::const_iterator it, iend;
int lHeap;
int d[N_MAX], H[N_MAX], P[N_MAX], apm[N_MAX];

inline void _swap(int& x, int& y) {int aux=x; x=y; y=aux;}
void DownHeap(int k)
{
    for(int son=k<<1; son <= lHeap; k=son, son<<=1)
    {
        if(son < lHeap && d[H[son]] > d[H[son+1]])
            ++son;
        if(d[H[k]] <= d[H[son]])
            return;
         _swap(H[k], H[son]);
         P[H[k]]=k;
         P[H[son]]=son;
    }
}
void UpHeap(int k)
{
    for(int key=d[H[k]], f=k>>1; k > 1 && key < d[H[f]]; k=f, f>>=1)
    {
        _swap(H[k], H[f]);
        P[H[k]]=k;
        P[H[f]]=f;
    }
}
inline void push(int x)
{
    H[++lHeap]=x;
    P[x]=lHeap;
    UpHeap(lHeap);
}
inline int pop()
{
    int r=H[1];
    P[H[1]]=-1;
    H[1]=H[lHeap];
    P[H[1]]=1;
    --lHeap;
    DownHeap(1);

    return r;
}
int main()
{
    int N, M, x, y, c, s=0, i;
    ifstream in("apm.in");
    ofstream out("apm.out");

    for(in>>N>>M; M; --M)
    {
        in>>x>>y>>c;
        G[x].push_back(pr(y,c));
        G[y].push_back(pr(x,c));
    }
    fill(d+1, d+N+1, oo);
    d[1]=0;
    for(push(1); lHeap;)
    {
        x=pop();
        s+=d[x];
        P[x]=-1;
        for(it=G[x].begin(), iend=G[x].end(); it < iend; ++it)
        {
            if(-1 == P[it->first])
                continue;
            if(oo == d[it->first])
            {
                d[it->first]=it->second;
                apm[it->first]=x;
                push(it->first);
            }
            else if(d[it->first] > it->second)
                 {
                     d[it->first]=it->second;
                     apm[it->first]=x;
                     UpHeap(P[it->first]);
                 }
        }
    }
    out<<s<<"\n"<<(N-1)<<"\n";
    for(i=2; i <= N; ++i)
        out<<i<<" "<<apm[i]<<"\n", s+=d[i];
    return EXIT_SUCCESS;
}