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#include <fstream>
#include <vector>
#define NDIM 200005
#define pb push_back
#define mkp make_pair
#define inf 200000200
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
int i,j,nod,n,m,a,b,c,x,v[NDIM],poz[NDIM],H[2*NDIM],hdim,vec[NDIM],sol;
vector < pair <int,int> > G[NDIM],apm;
void apm_insert(int x)
{
for(int i=0;i<G[x].size();i++)
{
int nod = G[x][i].first;
int cost = G[x][i].second;
v[nod]=min(v[nod],cost);
if(v[nod]==cost)
vec[nod]=x;
}
}
void H_up(int po)
{
int tata =po/2;
while(v[H[tata]] > v[H[po]] && tata >= 1)
{
swap(H[tata],H[po]);
swap(poz[H[tata]],poz[H[po]]);
tata/=2;po/=2;
}
}
void H_down(int po)
{
int fiu = 2*po;
while(fiu <= hdim)
{
if(fiu+1 <= hdim && v[H[fiu]] > v[H[fiu+1]])
fiu++;
if(v[H[fiu]] < v[H[po]])
{
swap(H[fiu],H[po]);
swap(poz[H[fiu]],poz[H[po]]);
po = fiu;
fiu = 2*po;
}
else
break;
}
}
void H_insert(int x)
{
H[++hdim] = x;
poz[x] = hdim;
H_up(hdim);
}
int H_extract()
{
int x = H[1];
poz[H[1]] = 0;
H[1] = H[hdim];
poz[H[1]] = 1;
hdim--;
return x;
}
int main()
{
fin>>n>>m;
for(i=1;i<=m;i++)
{
fin>>a>>b>>c;
G[a].pb(mkp(b,c));
G[b].pb(mkp(a,c));
}
for(i=1;i<=n;i++)
v[i]=inf;
v[1]=0;
apm_insert(1);
for(i=2;i<=n;i++)
{
H_insert(i);
}
for(i=1;i<n;i++)
{
x=H_extract();
apm_insert(x);
sol += v[x];
apm.pb(mkp(x,vec[x]));
for(j=0;j<G[x].size();j++)
{
nod=G[x][j].first;
if(poz[nod])
H_up(poz[nod]);
}
}
fout<<sol<<'\n'<<n-1<<'\n';
for(i=0;i<n-1;i++)
fout<<apm[i].first<<' '<<apm[i].second<<'\n';
return 0;
}