#pragma GCC optimize("Ofast,O2,O3,unroll-loops")
#pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;
void debug_out() { cerr << endl; }
template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
cerr << "[" << H << "]";
debug_out(T...);
}
#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define lla(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
clock_t startTime;
double getCurrentTime() {
return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}
#define MP make_pair
typedef long long ll;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const double eps = 0.000001;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 1e6 + 3e2;
const int M = 1248;
vector<pair<int, int>> g[N];
map<int, int> mp[N];
int d[N];
bool processed[N];
void solve(int TC) {
int n, m;
cin >> n >> m;
for (int i = 1; i <= m; i++){
int a, b, c, p;
cin >> a >> b >> c >> p;
g[a].emplace_back(b, c);
g[b].emplace_back(a, c);
mp[a][c]++;
mp[b][c]++;
}
for (int i = 1; i <= n; i++){
for (auto &e : g[i]){
int &c = e.second;
c = (mp[i][c] == 1 ? 0 : 1);
}
}
fill(d + 1, d + n + 1, INF);
priority_queue<pair<int, int>> pq;
pq.push(MP(0, 1));
d[1] = 0;
while (!pq.empty()){
int x = pq.top().second; pq.pop();
if (processed[x]) continue;
processed[x] = true;
for (auto now : g[x]){
int y = now.first, w = now.second;
if (d[y] > d[x] + w){
d[y] = d[x] + w;
pq.push(MP(-d[y], y));
}
}
}
if (!processed[n]){
cout << -1 << endl;
} else {
cout << d[n] << endl;
}
}
int main() {
startTime = clock();
ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
#ifdef dddxxz
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
int TC = 1;
//cin >> TC;
for (int test = 1; test <= TC; test++) {
//debug(test);
//cout << "Case #" << test << ": ";
solve(test);
}
#ifdef dddxxz
cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;
#endif
return 0;
}
