/*
ID: swagchicken1
PROG:
LANG: C++11
*/
#include <iostream>
#include <tuple>
#include <cmath>
#include <string>
#include <cstring>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <algorithm>
#include <vector>
#include <fstream>
#include <iomanip>
#include <ctime>
#include <cctype>
#include <climits>
#include <chrono>
#include <numeric>
#include <functional>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector< vector <int> > vvi;
typedef pair<int, int> pii;
typedef pair < pair < int, int >, int > piii;
typedef pair < pair <int, int > , pair <int, int> > piiii;
typedef pair<ll, ll> pll;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<string> vs;
#define FOR(i,a,b) for(int i = a; i < b; i ++)
#define RFOR(i,a,b) for(int i = a-1; i >= b; i --)
#define all(a) a.begin(), a.end()
#define endl '\n';
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define ff first
#define ss second
template <typename T>
void pr(vector<T> &v) {
FOR(i, 0, sz(v)) cout << v[i] << " ";
cout << endl;
}
template <typename T>
void pr(vector<vector<T> > &v) {
FOR(i, 0, sz(v)) { pr(v[i]); }
}
template <typename T>
void re(T &x) {
cin >> x;
}
template <typename T>
void re(vector<T> &a) {
FOR(i, 0, sz(a)) re(a[i]);
}
template <class Arg, class... Args>
void re(Arg &first, Args &... rest) {
re(first);
re(rest...);
}
template <typename T>
void pr(T x) {
cout << x << endl;
}
template <class Arg, class... Args>
void pr(const Arg &first, const Args &... rest) {
cout << first << " ";
pr(rest...);
cout << endl;
}
void ps() { cout << endl; }
template<class T, class... Ts>
void ps(const T& t, const Ts&... ts) {
cout << t; if (sizeof...(ts)) cout << " "; ps(ts...);
}
const ll MOD = 1000000007;
#define inf 1e18;
#define INF INT_MAX
//#define DEBUG
long double PI = 4*atan(1);
long double eps = 1e-9;
vector<vector<pair<int, ll>>> adj;
map<pii, ll> weights;
map<pii, ll> cols;
map<int, map<int, vector<int>>> nodecols;
vector<pii> edges;
vector<ll> dist;
void dijkstra(int start) {
int N = dist.size();
FOR(i,0,N) dist[i] = 1e18;
dist[start] = 0;
set<pair<ll, int>> pq;
pq.insert({0, start});
while(!pq.empty()) {
pair<ll, int> curr = *pq.begin();
pq.erase(pq.find(curr));
int u = curr.ss;
ll d = curr.ff;
for(pair<int, ll> nxt : adj[u]) {
int v = nxt.ff; ll w = nxt.ss;
if(d + w < dist[v]) {
if(pq.find({dist[v], v}) != pq.end()) pq.erase(pq.find({dist[v], v}));
dist[v] = d+w;
pq.insert({d + w, v});
}
}
}
}
int main() {
//auto start = chrono::high_resolution_clock::now();
ios_base::sync_with_stdio(0);cin.tie(0);
//ofstream cout("output.txt");
//ifstream cin("input.txt");
#ifdef DEBUG
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
// freopen("cowmbat.in", "r", stdin);
// freopen("cowmbat.out", "w", stdout);
#endif
int n,m; cin >> n >> m;
adj.resize(n);
dist.resize(n);
FOR(i,0,m) {
int u,v; cin >> u >> v; u--; v--;
ll c,p; cin >> c >> p;
edges.pb({u,v});
weights[{u,v}] = p;
cols[{u,v}] = c;
nodecols[u][c].pb(v);
nodecols[v][c].pb(u);
}
int tot = n;
for(pii x : edges) {
int u = x.ff, v = x.ss;
int c = cols[{u,v}];
ll cost = weights[{u,v}];
int cnt1 = nodecols[u][c].size();
int cnt2 = nodecols[v][c].size();
// cout << u << " " << v << endl;
// cout << c << endl;
// cout << cnt1 << " " << cnt2 << endl;
// cout << endl;
if(cnt1 == 2) {
vector<pair<int, ll>> newnode;
adj.pb(newnode);
adj[v].pb({tot, cost});
adj[u].pb({tot, cost});
adj[tot].pb({u, 0});
int other = ((nodecols[u][c][0] != v) ? nodecols[u][c][0] : nodecols[u][c][1]);
adj[tot].pb({other, 0});
dist.pb(0);
tot++;
}
if(cnt2 == 2) {
vector<pair<int, ll>> newnode;
adj.pb(newnode);
adj[u].pb({tot, cost});
adj[v].pb({tot, cost});
adj[tot].pb({v, 0});
int other = ((nodecols[v][c][0] != u) ? nodecols[v][c][0] : nodecols[v][c][1]);
adj[tot].pb({other, 0});
dist.pb(0);
tot++;
}
if(cnt1 == 1) {
adj[u].pb({v, 0});
}
if(cnt2 == 1) {
adj[v].pb({u, 0});
}
if(cnt1 > 1) {
adj[u].pb({v, cost});
}
if(cnt2 > 1) {
adj[v].pb({u, cost});
}
}
// FOR(i,0,tot) {
// cout << "NODE " << i << endl;
// for(pair<int, ll> x : adj[i]) {
// cout << x.ff << " " << x.ss << endl;
// }
// cout << "----------" << endl;
// }
dijkstra(0);
cout << dist[n-1] << endl;
//auto stop = chrono::high_resolution_clock::now();
//auto duration = chrono::duration_cast<chrono::microseconds>(stop - start);
//cout << duration.count() << endl;
//cin.close();
//cout.close();
}
