#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define mk make_pair
#define S second
#define int long long
int n,m;
int sz[300005];
int par[300005];
vector<tuple<int,int,int>> edges;
vector<pair<int,int>> adj[300005];
int fin(int x){
    if(par[x]==x) return x;
    else return par[x]=fin(par[x]);
}
bool same(int x, int y){
    x=fin(x), y=fin(y);
    return x==y;
}
void unite(int x, int y){
    x=fin(x), y=fin(y);
    if(x==y){
        return;
    }
    if(sz[x]<sz[y]) swap(x,y);
    sz[x]+=sz[y];
    par[y]=x;
}
void dfs(int node, int pre, int we){
    if(node==n){
        cout<<we<<endl;
        return;
    }
    for( pair<int,int> i: adj[node]){
        if(i.second!=pre){
            dfs(i.second,node,we+i.first);
        }
    }
}
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(NULL);
	cin>>n>>m;
	for(int i=0; i<m; i++){
        int u,v,w;
        cin>>u>>v>>w;
        edges.push_back({w,u,v});
      //  adj[u].push_back({w,v});
        //adj[v].push_back({w,u});
	}
    for(int i=0; i<=n; i++){
        sz[i]=1;
        par[i]=i;
    }
    priority_queue<int> q;
    sort(edges.begin(),edges.end());
    for(auto [w,u,v] : edges){
        if(!same(u,v)){
            unite(u,v);
            adj[u].push_back({w,v});
            adj[v].push_back({w,u});
            q.push(w);
        }
      //  cout<<":L"<<endl;
        //cout<<w<<" "<<u<<" "<<v<<endl;
        int x=1, y=n;
        x=fin(x), y=fin(y);
        if(x==y){
             break;
        }
    }
    dfs(1,0,0);

}