#include <fstream>
#include <vector>
#include <utility>
#define NMAX 100000

using namespace std;

ifstream f("file.in");
ofstream g("rf.out");

int n,m;
vector <pair <int,int>> v[NMAX];
vector <int> viz;
priority_queue <pair <int,pair <int,int>>> h;

int main()
{
    f>>n>>m;
    for(int i=0;i<n;++i)
        viz.push_back(0);
    while(m--)
    {
        int x,y,z;
        f>>x>>y>>z;
        v[x].push_back(make_pair(y,z));
    }
    for(auto x:v[0])
        h.push(make_pair(x.second,make_pair(0,x.first)));
    viz[0]=1;
    while(!h.empty())
    {
        pair<int,pair<int,int>> e=h.top();
        h.pop();
        viz[e.second.second]=1;
        for(auto x:v[e.second.second])
            if(!viz[x.first])
                h.push(make_pair(x.second,make_pair(e.second.second,x.first)));
    }

    return 0;
}