#include <bits/stdc++.h>
// Author: Kazuki_Will_Win_VOI_8703
#define fi first
#define se second
#define pii pair<int, int>
#define int long long
#define all(a) a.begin(), a.end()
using namespace std;
const int mn = 1e5 + 5, inf = 1e18;
int n, m, d[mn], cnt[mn];
vector <tuple<int, int, int>> a[mn];
void solve(){
cin >> n >> m;
for(int i = 1; i <= m; i++){
int u, v, c, p; cin >> u >> v >> c >> p;
a[u].push_back({v, c, p});
a[v].push_back({u, c, p});
}
fill(d, d + mn, inf);
priority_queue<pii, vector<pii>, greater<pii>> pq;
d[1] = 0;
pq.push({d[1], 1});
while(pq.size()){
auto [c, u] = pq.top();
pq.pop();
if(c > d[u]) continue;
for(auto [v, c, p] : a[u]) cnt[c] ++;
for(auto [v, c, p] : a[u]){
if(cnt[c] >= 2){
if(d[v] > d[u] + p){
d[v] = d[u] + p;
pq.push({d[v], v});
}
}
else{
if(d[v] > d[u]){
d[v] = d[u];
pq.push({d[v], v});
}
}
}
for(auto [v, c, p] : a[u]) cnt[c] = 0;
}
cout << d[n] << '\n';
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int t = 1;
// cin >> t;
while(t--) solve();
}
