#include<bits/stdc++.h>
using namespace std;
int n,m,fa[100005],t[300005],d=1e9;
int ans;
bool ca[3000005]; 
struct node{
	int u,v,w;
}a[300005]; 
int find(int x){
	if(fa[x]!=x){
		return fa[x]=find(fa[x]);
	}
	return fa[x];
}
void he(int a,int b){
	int x=find(a),y=find(b);
	if(x!=y)
		fa[x]=y;
}
int k;
void shu(){
	int tot=0;
	for(int i=1;i<=m;i++){
		int x=find(a[i].u);
		int y=find(a[i].v);
		if(x!=y){
			fa[x]=y;
			tot++;
			ans+=a[i].w;
			ca[i]=1;
		}
		if(tot>=n-1)return;
	}
}
void f(){
	for(int i=1;i<=m;i++){
		if(a[i].w==a[i-1].w){
			t[i]=t[i-1];//cout<<i<<" "<<a[i].w<<" "<<k<<endl;
		}else{
			t[i]=k;//cout<<i<<" "<<a[i].w<<" "<<k<<endl;
		}
		if(ca[i]==1){
			k=i;
		}
	}
}
bool cmp(node a,node b){
	return a.w<b.w;
}
int main(){
	freopen("secmst.in","r",stdin);
	freopen("secmst.out","w",stdout);
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		cin>>a[i].u>>a[i].v>>a[i].w;
	}
	for(int i=1;i<=n;i++){
		fa[i]=i;
	}
	sort(a+1,a+m+1,cmp);shu();f();
	for(int i=1;i<=m;i++){
		int x=find(a[i].u),y=find(a[i].v);
		if(ca[i]!=1&&x==y){
			//cout<<i<<" ";
			//cout<<a[i].u<<" "<<a[i].v<<" "<<a[i].w<<" "<<a[t[i]].w<<endl;
			d=min(d,a[i].w-a[t[i]].w);
		}
	}
	cout<<ans+d;
	return 0;
}