#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

const int MAXN = 1000;

struct Edge
{
    int from, to, price;
    Edge( int f, int t, int p ) : from(f), to(t), price(p) {}
    bool operator<( const Edge& e ) const
    {
        return price < e.price;
    }
};

int N, M, parent[MAXN], rankk[MAXN];
vector <Edge> edges;

void input()
{
    scanf("%d %d", &N, &M);
    int f, t, p;
    for( int i = 0; i < M; i++ )
    {
        scanf("%d %d %d", &f, &t, &p);
        edges.push_back(Edge(f, t, p));
        parent[edges[i].from-1] = edges[i].from-1;
        parent[edges[i].to-1] = edges[i].to-1;
    }
}

void union_trees( int from, int to )
{
    if( rankk[from] == rankk[to] )
    {
        parent[to] = from;
        rankk[from]++;
    }
    else if( rankk[from] < rankk[to] )
    {
        parent[from] = to;
    }
    else
    {
        parent[to] = from;
    }
}

int find( int node )
{
    if( parent[node] == node )
    {
        return node;
    }

    return parent[node] = find(parent[node]);
}

void kruskal()
{
    sort(edges.begin(), edges.end());

    int i = 0, ans = 0, br = 0;
    while( br < N-1 )
    {
        int p1 = find(edges[i].from);
        int p2 = find(edges[i].to);
        if( p1 != p2 )
        {
            union_trees(p1, p2);
            br++;
            ans += edges[i].price;
        }
        i++;
    }
    printf("%d\n", ans);
}


int main()
{
    input();
    kruskal();

    return 0;
}
/**

6 10
1 2 1
3 6 1
3 1 2
3 2 4
1 6 3
5 3 2
3 4 1
4 5 1
4 2 10
2 5 1

**/