#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pii;
#define mp make_pair
#define pb push_back
#define F first
#define S second
#define debug(x) std::cout << #x << ": " << x << "\n"
#define all(v) v.begin(), v.end()
#define li(i,a,b) for (int (i) = (a); (i) < (b); (i)++)
#define endl '\n'
#define mem(name,val) memset(name,val,sizeof(name))
#define min(a,b) (a<=b ? a : b)
#define max(a,b) (a>=b ? a : b)
//using u64 = uint64_t;
//using u128 = __uint128_t;
const int nmax = 1e5+3;
const ll inf = 1e18;
vector<array<ll,3>> adj[nmax];
map<int,int> cf[nmax]; // color freq for each city
int main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
int n,m,a,b,c;
ll p ;
cin>>n>>m;
li(i,0,m){
cin>>a>>b>>c>>p;
adj[a].pb({b,c,p});
adj[b].pb({a,c,p});
cf[a][c]++;
cf[b][c]++;
}
// dijk
vector<ll> d(nmax,inf);
d[1]=0;
priority_queue<pii, vector<pii>, greater<pii>> pq;
pq.push({0,1});
while(!pq.empty()){
const auto [d_v, v] = pq.top();
pq.pop();
if(d_v!=d[v])continue;
for(const auto [to, col, cost] : adj[v]){
if(cf[v][col]==1 && d_v < d[to]){
d[to]=d_v;
pq.push({d[to],to});
}
else if(cf[v][col]!=1 && d_v + cost < d[to]){
d[to]=d_v+cost;
pq.push({d[to],to});
}
}
}
if(d[n]==inf){
cout<<-1<<endl;
}
else{
cout<<d[n]<<endl;
}
return 0;
}
