#include <fstream>
#include <climits>
using namespace std;
int a[65][65];
int t[65];
bool v[65];
int main()
{
    ifstream f("traseu.in");
    ofstream g("traseu.out");
    int i,j,n,m,u,x,y,k,cost,n1,n2,ct=0;
    f>>n>>m;
    for (i=1;i<=m;i++)
    {
        f>>x>>y>>u;
        a[x][y]=a[y][x]=u;
    }
    v[1]=true;
    for (k=2;k<=n;k++)
    {
        cost=INT_MAX;
        n1=n2=-1;
        for (i=1;i<=n;i++)
            for (j=1;j<=n;j++)
            if (v[i]&&!v[j])
                if (a[i][j])
                    if (a[i][j]<cost)
                    {
                        cost=a[i][j];
                        n1=i;n2=j;
                    }
        v[n2]=true;
        t[n2]=n1;
        ct+=a[n1][n2];
    }
    g<<ct<<'\n';

    f.close();
    g.close();
    return 0;
}