#include <utility>

#include <vector>

#include <algorithm>

using namespace std;

int id[10001];

int edges;

void initialize(int n)

{

for(int i=0;i<(n+1);i++)

id[i]=i;

}

int root(int i)#include <iostream>

#in

{

while(id[i]!=i)

{

id[i]=id[id[i]];

i=id[i];

}

return i;

}

void unixo(int x,int y)

{

int p=root(x);

int q=root(y);

id[p]=id[q];

}

int kruskal(vector<pair<int ,pair<int ,int > > > a)

{int x,y;

long long min=0,cost;

for(int i=0;i<edges;i++)

{

cost=a[i].first;

x=a[i].second.first;

y=a[i].second.second;

if(root(x)!=root(y))

{

min+=cost;

unixo(x,y);

}

}

return min;

}

int main()

{

int n;

cin>>n>>edges;

initialize(n);

vector<pair<int ,pair<int ,int > > > a;

for(int i=0;i<edges;i++)

{

int d,b,c;

cin>>b>>c>>d;

a.push_back(make_pair(d,make_pair(b,c)));

}

sort(a.begin(),a.end());

int minxd=kruskal(a);

cout<<minxd;

return 0;

}