#include <bits/stdc++.h>
using namespace std ;
const long long inf = 1e18 ;
const int MAX = 1e5 + 10 ;
int arr[MAX] ;
int n , m ;
vector< vector< array<int , 3> > >adj(MAX) ;
long long dist[MAX] ;
map< pair<int , int> , long long>mp , mp2 ;
void dijkstra(int src)
{
for(int i = 1 ; i <= n ; ++i)
dist[i] = inf ;
priority_queue< pair<long long , int> , vector< pair<long long , int> > , greater< pair<long long , int> > >q ;
dist[src] = 0 ;
q.push({0 , src}) ;
while(!q.empty())
{
pair<long long , int>p = q.top() ;
q.pop() ;
int node = p.second ;
long long cost = p.first ;
if(dist[node] < cost)
continue ;
for(auto &childd : adj[node])
mp2[{node , childd[0]}] = max(mp2[{node , childd[0]}] , 1ll * childd[2] - (dist[childd[1]] + childd[2] - dist[node])) ;
for(auto &childd : adj[node])
{
int child2 = childd[1] ;
long long cost2 = cost + min(1ll * childd[2] , mp[{node , childd[0]}] - childd[2] - mp2[{node , childd[0]}]) ;
if(cost2 < dist[child2])
{
dist[child2] = cost2 ;
q.push({cost2 , child2}) ;
}
}
}
}
int main()
{
ios_base::sync_with_stdio(0) ;
cin.tie(0) ;
cin>>n>>m ;
for(int i = 0 ; i < m ; ++i)
{
int x , y , c , w ;
cin>>x>>y>>c>>w ;
adj[x].push_back({c , y , w}) ;
adj[y].push_back({c , x , w}) ;
mp[{x , c}] += w , mp[{y , c}] += w ;
}
dijkstra(1) ;
if(dist[n] == inf)
dist[n] = -1 ;
return cout<<dist[n]<<"\n" , 0 ;
}
