#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define pb push_back
#define eb emplace_back
#define pii pair<int,int>
#define X first
#define Y second
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T i, U ...j) {
cout << i << ' ', abc(j...);
}
template <typename T> void printv(T l, T r) {
for (; l != r; ++l) cout << *l << " \n"[l + 1 == r];
}
#ifdef Doludu
#define test(x...) abc("[" + string(#x) + "]", x)
#define owo freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#else
#define test(x...) void(0)
#define owo ios::sync_with_stdio(false), cin.tie(0)
#endif
const int N = 100000;
struct edge {
int v, c, p;
};
vector <edge> adj[N];
int main () {
owo;
int n, m;
cin >> n >> m;
for (int i = 0, u, v, c, p; i < m; ++i) {
cin >> u >> v >> c >> p, --u, --v, --c;
adj[u].pb({v, c, p});
adj[v].pb({u, c, p});
}
vector <vector <pair <int, int>>> adj2(n);
vector <lli> cost(m, 0);
for (int i = 0; i < n; ++i) {
for (edge &e : adj[i]) {
cost[e.c]++;
}
for (edge &e : adj[i]) {
adj2[i].eb(e.v, cost[e.c] == 1 ? 0 : 1);
}
for (edge &e : adj[i]) {
cost[e.c] = 0;
}
}
vector <lli> dis(n, 1ll << 60);
dis[0] = 0;
priority_queue <pair <lli, int>, vector <pair <lli, int>>, greater <pair <lli, int>>> pq;
pq.emplace(dis[0], 0);
while (!pq.empty()) {
lli d; int v; tie(d, v) = pq.top(); pq.pop();
if (d > dis[v])
continue;
for (auto [u, w] : adj2[v]) if (dis[u] > dis[v] + w) {
dis[u] = dis[v] + w;
pq.emplace(dis[u], u);
}
}
if (dis[n - 1] == 1ll << 60)
dis[n - 1] = -1;
cout << dis[n - 1] << endl;
}
