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#include <iostream>
#include <fstream>
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
int n,m;
struct muchie{
int x;
int y;
int c;
}v[200003];
int c[200003];
struct solutie{
int x1;
int y1;
}sol[200003];
int pozitie(int st,int dr)
{
muchie val=v[st];
while(st<dr)
{
while(st<dr&&v[dr].c>=val.c)
dr--;
v[st]=v[dr];
while(st<dr&&v[st].c<=val.c)
st++;
v[dr]=v[st];
}
v[st]=val;
return st;
}
void quicksort(int st,int dr)
{
int poz=pozitie(st,dr);
if(st<poz-1)
quicksort(st,poz-1);
if(dr>poz+1)
quicksort(poz+1,dr);
}
int main()
{
int i;
f>>n>>m;
for(i=1;i<=m;i++)
f>>v[i].x>>v[i].y>>v[i].c;
quicksort(1,m);
//krskal
for(i=1;i<=n;i++)
c[i]=i;//fiecaruinod il punem intrun arbore diferit
int a,cost=0;
int nr=0;
i=1;
while(nr<n-1)
{
if(c[v[i].x]!=c[v[i].y]) //daca nodurile fac parte din multimi diferite
{
nr++;
sol[nr].x1=v[i].x; //adaugam la solutie muchia
sol[nr].y1=v[i].y;
cost=cost+v[i].c; //calculam costul
a=c[v[i].y];
for(int j=1;j<=n;j++) //schimbam toate elementele care fac parte din alta multime in multimea arborelui
if(c[j]==a)
c[j]=c[v[i].x];
}
i++;
}
g<<cost<<"\n";
g<<n-1<<"\n";
for(i=1;i<=n-1;i++)
g<<sol[i].x1<<" "<<sol[i].y1<<"\n";
return 0;
}