#include<stdio.h>#include<queue>using namespace std;#define MAX 99999int father[MAX];struct Edge{  int a;  int b;  int dist;  bool operator<(const Edge & e) const  {       if(dist>e.dist)         return true;    return false;  }}edge[MAX];void init(int n){  for(int i=1;i<=n;i++)  {     father[i]=i;  }}int find(int x){  while(x!=father[x])  {     x=father[x];  }  return x;}void merge(int a,int b){    int i=find(a);    int j=find(b);    if(i!=j)    {       father[i]=j;    }}int main(){    int n,m;    int a,b,d;    Edge tmp;    priority_queue<Edge> q;    while(scanf("%d%d",&n,&m)!=EOF)    {       init(n);       for(int i=0;i<m;i++)       {          scanf("%d%d%d",&tmp.a,&tmp.b,&tmp.dist);          q.push(tmp);       }       int sum=0;       while(!q.empty())       {          tmp = q.top();          //printf("11%d %d %d\n",tmp.a,tmp.b,tmp.dist);          int a=find(tmp.a);          int b=find(tmp.b);          if(a!=b)          {             merge(a,b);             printf("%d %d\n",tmp.a,tmp.b);             sum+=tmp.dist;          }          q.pop();       }       printf("%d\n",sum);    }    getchar();    return 0;}