#include <bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> pi;
#define f first
#define s second
#define FAST ios_base::sync_with_stdio(0); cin.tie(0);
#define all(x) x.begin(),x.end()
const int maxn = 100010;
const int INF = LLONG_MAX/2;
const int mod = 1e9+7;
typedef pair<int, pi> pii;
//struct edge {
//int v, c, p;
//};
map <int, vector <pii>> adjlist[maxn];
map <int, int> dp[maxn], sum[maxn];
int dist[maxn];
int n, e;
int32_t main() {
FAST
cin >> n >> e;
for (int i =0;i<e;i++) {
int a,b, c, p;
cin >> a >> b >> c >> p;
adjlist[a][c].push_back(pii(b,pi(c,p)));
adjlist[b][c].push_back(pii(a,pi(c,p)));
sum[a][c] += p;
sum[b][c] += p;
}
//(1) Only change edge i to completely unique colour (guaranteed to exist)
//(2) Change rest of edges with same colour as edge i
memset(dist,-1,sizeof dist);
priority_queue<pii, vector<pii>,greater<pii>> pq;
pq.push(pii(0,pi(1,0)));
dist[1] = 0;
while (!pq.empty()) {
auto [d, cur] = pq.top(); pq.pop();
auto [x, c] = cur;
if (c != 0) {
//We must take a (2) here if not void
if (d != dp[x][c]) continue;
for (auto [v,xx] : adjlist[x][c]) {
auto [cc, p] = xx;
//if (cc != c) continue;
int nd = d + sum[x][c] - p;
if (dist[v] == -1 or dist[v] > nd) {
pq.push(pii(nd,pi(v,0)));
dist[v] = nd;
}
}
} else {
if (d != dist[x]) continue;
for (auto gaygay : adjlist[x]) {
for (auto [v, xx]: gaygay.s) {
auto [cc, p] = xx;
int nd = d + p;
//Take a (1)
//Straight to dist
if (dist[v] == -1 or dist[v] > nd) {
dist[v] = nd;
pq.push(pii(nd,pi(v,0)));
}
//Do a suspension
nd = d;
if (dp[v].count(cc) == 0 or dp[v][cc] > nd) {
dp[v][cc] = nd;
pq.push(pii(nd,pi(v,cc)));
}
//Take a (2)
nd = d + sum[x][cc] - p;
if (dist[v] == -1 or dist[v] > nd) {
dist[v] = nd;
pq.push(pii(nd,pi(v,0)));
}
}
}
}
}
cout << dist[n];
}
