#include<bits/stdc++.h>
#define ll long long

using namespace std;

void vout(vector<ll>&v,ll n)
{
    for(ll i=1;i<=n;i++)
    {

        cout<<v[i]<<" ";
    }
}
vector<ll>vis(100005,0);
ll prims(ll src,ll n,vector<vector<pair<ll,ll>>>&graph)
{
    ll cost=0;
    priority_queue<pair<ll,ll>,vector<pair<ll,ll>>,greater<pair<ll,ll>>>pq;
    pq.push({0,src});
    ll cnt=0;
    while(cnt!=n)
    {
        pair<ll,ll>pr;
        pr=pq.top();
        pq.pop();
        if(!vis[pr.second])
        {
            vis[pr.second]=1;
            cost+=pr.first;
            cnt++;
            for(auto x:graph[pr.second])
            {
               if(!vis[x.second])
                    pq.push(x);

            }
        }
    }
    return cost;
}
int main()
{
    ll i,n,m,x,y,z;
    cin>>n>>m;
    vector<vector<pair<ll,ll>>>graph(n+1);
    for(i=0;i<m;i++)
    {
        cin>>x>>y>>z;
        graph[x].push_back({z,y});
        graph[y].push_back({z,x});
    }
    cout<<prims(1,n,graph)<<endl;
}