#include<iostream>
#include<cstdio>
#include<queue>
#include<string>
#include<cstring>
using namespace std; 
struct node{
    int id;
    int ml;
    const bool operator < (node b) const{
        return ml>b.ml;
    }
};
int a[5100][5100],n,m;
priority_queue<node> v;
priority_queue<node> u;
node make(int x,int y){
    node ret;
    ret.id = x;
    ret.ml = y;
    return ret;
}
void prim(){
    int cnt = 1,cost=0;
    node vlist[5100];
    int len=1;
    u.push(make(1,0));
    for(int i = 2; i <= n; i++) v.push(make(i,a[1][i]));
    while(cnt<=n&&!v.empty()){
         node vfi = v.top();
         v.pop();
         u.push(vfi);
         //printf("the best one:%d-%d\n",vfi.id,vfi.ml);
         cost+=vfi.ml;
         cnt++;
         len = v.size();
         for(int i = 1; i <= len; i++){
            vlist[i] = v.top();
            v.pop();
            vlist[i].ml = min(vlist[i].ml,a[vlist[i].id][vfi.id]);
         }
         for(int i = 1; i <= len; i++){
            v.push(vlist[i]);
         }
    }
    if(cnt!=n) cout << "orz";
    else cout << cost;
}
int main(){
    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n; j++) a[i][j] = 100000;
    }
    for(int i = 1,x,y,z; i <= m; i++){
        cin >> x >> y >> z;
        //cout << a[x][y] << " " << z <<"-----";
        a[x][y] = min(a[x][y],z);
        a[y][x] = a[x][y];
        //cout << a[x][y] << " " << a[y][x] << endl;
    }
    prim();
    return 0;
}

TLE:#8,#9,#10

WA:#13(无解)