#include <stdio.h>#include <string.h>#include <stdlib.h>struct node{    int u,v,w;}q[200001];int bin[50001];int n,m,ans;int cmp(const void *a,const void *b){    struct node *x;    struct node *y;    x = (struct node *)a;    y = (struct node *)b;    return x->w - y->w;}int find(int x){    int r,k,j;    r = x;    while(bin[r]!=r)    r = bin[r];    j = x;    while(j!=r)    {        k = bin[j];        bin[j] = r;        j = k;    }    return r;}void kruskal(){    int i;    for(i = 1;i<=n;i++)    {        bin[i] = i;    }    for(i = 0;i<m;i++)    {        int uu = find(q[i].u);        int vv = find(q[i].v);        if(uu!=vv)        {            bin[uu] = vv;            ans+=q[i].w;        }    }    printf("%d\n",ans);}int main(){    int i,j;    while(~scanf("%d%d",&n,&m))    {        ans = 0;        for(i = 0;i<m;i++)        {            scanf("%d%d%d",&q[i].u,&q[i].v,&q[i].w);        }        qsort(q,m,sizeof(q[0]),cmp);        kruskal();    }    return 0;}