#include<bits/stdc++.h>
#define int long long
using namespace std;
vector<pair<int,pair<int,int>>>temp[200005];
vector<pair<int,int>>adj[200005];
vector<pair<int,pair<int,int>>>res[200005];
int val[200005];
int cnt[200005];
int dis[200005];
int inf=1e18;
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int n,m;cin>>n>>m;
for(int i=1;i<=m;i++){
int a,b,c,p;cin>>a>>b>>c>>p;
temp[a].push_back({b,{c,p}});
temp[b].push_back({a,{c,p}});
}
for(int i=1;i<=n;i++){
vector<int>v;
for(auto x:temp[i]){
int c=x.second.first;
int p=x.second.second;
cnt[c]++;
res[c].push_back(x);
v.push_back(c);
}
sort(v.begin(),v.end());
v.erase(unique(v.begin(),v.end()),v.end());
for(auto x:v){
if(cnt[x]==2){
auto e1=res[x][0];
auto e2=res[x][1];
adj[e1.first].push_back({e2.first,e1.second.second});
adj[e2.first].push_back({e1.first,e2.second.second});
}
}
for(auto x:temp[i]){
int go=x.first;
int c=x.second.first;
int p=x.second.second;
if(cnt[c]==1)adj[i].push_back({go,0});
else{
adj[i].push_back({go,p});
}
}
for(auto x:temp[i]){
int c=x.second.first;
int p=x.second.second;
cnt[c]--;
res[c].clear();
}
}
for(int i=1;i<=n;i++)dis[i]=inf;
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>pq;
pq.push({0,1});
while(!pq.empty()){
auto [cost,u]=pq.top();
pq.pop();
if(dis[u]!=inf)continue;
dis[u]=cost;
for(auto x:adj[u]){
pq.push({cost+x.second,x.first});
}
}
if(dis[n]==inf)cout<<"-1\n";
else cout<<dis[n];
}
