#include<fstream.h>
#define N 200001
#define INF 10000000
typedef struct nod
{long info,cost;
struct nod *urm;}Nod,*list;
long n,m,i,j,k,a,b,c,d[N],poz[N],h[N],s,t,e=0,l[N],r,par[N],min;
list g[N],p;
void add(long h[N],long *n,long poz[N],long v[N],long j)
{h[++(*n)]=j;
poz[j]=(*n);
long t=(*n),key=h[(*n)],x,y;
while(t>1&&v[key]<v[h[t/2]])
     {x=h[t],h[t]=h[t/2],h[t/2]=x;
     y=poz[h[t]],poz[h[t]]=poz[h[t/2]];
     poz[h[t/2]]=y,t/=2;}}

void del(long h[N],long *n,long k,long poz[N],long v[N])
{long key,son,aux,x,y,z,t=h[k];
h[k]=h[(*n)],h[(*n)]=t;
z=poz[h[(*n)]];
poz[h[(*n)--]]=poz[h[k]];
poz[h[k]]=z;
if(k>1&&v[h[k]]<v[h[k/2]])
     {key=h[k];
     x=poz[h[k/2]];
     y=poz[h[k]];  
     while(k>1&&v[key]<v[h[k/2]])
            {t=poz[h[k]];
            poz[h[k]]=poz[h[k/2]];
            poz[h[k/2]]=t;
            z=h[k],h[k]=h[k/2];
            h[k/2]=z,k/=2;}}
else
     {do
            {son=0;
            if(2*k<=(*n))
                    {son=2*k;
                    if(2*k+1<=(*n)&&v[h[2*k+1]]<v[h[2*k]])
                            son=2*k+1;
                    if(v[h[son]]>=v[h[k]])
                            son=0;}
            if(son)
                    {aux=h[k],h[k]=h[son];
                    h[son]=aux,t=poz[h[son]];
                    poz[h[son]]=poz[h[k]];
                    poz[h[k]]=t,k=son;}}
     while(son);}}

void push(list &q,long x,long y)
{Nod *p=new Nod;
p->info=x,p->cost=y;
p->urm=q;
q=p;}

void modific(long h[N],long n,long d[N],long poz[N],long l,long k)
{long i,x,y,z;
if(k<=d[h[l]])
     {d[h[l]]=k;
     i=l,z=h[l];
     while(i>1&&d[h[i/2]]>d[z])
            {x=h[i],h[i]=h[i/2];
            h[i/2]=x,y=poz[h[i]];
            poz[h[i]]=poz[h[i/2]];
            poz[h[i/2]]=y,i/=2;}}}
int main()
{ifstream f("apm.in");
ofstream z("apm.out");
f>>n>>m;
for(j=0;j<n;j++)
     {g[j]=NULL;
     d[j]=INF;
     par[j]=-1;
     l[j]=0;}
while(m--)
     {f>>a>>b>>c;
     a--,b--;
     push(g[a],b,c);
     push(g[b],a,c);}
d[0]=j=0;
for(i=0;i<n;i++)
     add(h,&j,poz,d,i);
while(j!=0)
     {i=h[1],l[i]=1;
     del(h,&j,poz[i],poz,d);
     for(p=g[i];p!=NULL;p=p->urm)
     if(l[p->info]==0&&p->cost<d[p->info])
           {d[p->info]=p->cost,par[p->info]=i;
           modific(h,j,d,poz,poz[p->info],d[p->info]);}}
for(k=0,i=0;i<n;i++)
if(par[i]!=-1)
     e+=d[i],k++;
z<<e<<"\n"<<k<<"\n";
for(j=0;j<n;j++)
if(par[j]!=-1)
     z<<j+1<<" "<<par[j]+1<<"\n";
f.close();
z.close();
return 0;}