#include <fstream>
#include <vector>
#include <queue>
#define inf 1000000001
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
const int N=2e5+1;
int n,m,d[N],pred[N],cost;
vector <pair<int,int>> a[N];
priority_queue <pair<int,int>> q;
bool selectat[N];
int prim(){
for(int i=1; i<=n; i++)
d[i]=inf;
d[1]=0;
q.push({0,1});
while(!q.empty()){
int x=q.top().second;
q.pop();
if(selectat[x])
continue;
selectat[x]=1;
cost+=d[x];
for(auto j:a[x]){
int y=j.first;
int c=j.second;
if(selectat[y])
continue;
if(c<d[y]){
d[y]=c;
pred[y]=x;
q.push({-c,y});
}
}
}
return cost;
}
int main()
{
f>>n>>m;
for(int i=1; i<=m; i++){
int x,y,c;
f>>x>>y>>c;
a[x].push_back({y,c});
a[y].push_back({x,c});
}
g<<prim()<<'\n'<<n-1<<'\n';
for(int i=2; i<=n; i++)
g<<i<<" "<<pred[i]<<'\n';
return 0;
}