#include<bits/stdc++.h>
#define ll long long
using namespace std;
mt19937 myrand(time(0));
inline ll read(){
	ll x=0,w=1;
	char ch=0;
	while(ch<'0'||ch>'9'){
		if(ch=='-')w=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		x=(x<<3)+(x<<1)+(ch^48);
		ch=getchar();
	}
	return x*w;
}
int n,m,ans;
struct edge{
	int u,v,w;
	bool operator <(const edge a)const{
		return w<a.w;
	}
}e[200005];
int fa[5005];
int find(int x){
	return fa[x]==x?x:fa[x]=find(fa[x]);
}
void kru(){
	int cnt=0;
	sort(e+1,e+n+1);
	for(int i=1;i<=m;i++){
		int a=find(e[i].u),b=find(e[i].v);
		if(a==b)continue;
		fa[a]=b;
		ans+=e[i].w;
		cnt++;
		if(cnt==n-1)return;
	}
}
int main(){
	n=read();m=read();
	for(int i=1;i<=n;i++)fa[i]=i;
	for(int i=1;i<=m;i++){
		e[i].u=read();
		e[i].v=read();
		e[i].w=read();
	}
	kru();
	cout<<ans;
	return 0;
}