#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;
};
vector <edge> 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].push_back({b,c,p});
adjlist[b].push_back({a,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 i : adjlist[x]) {
if (i.c != c) continue;
int nd = d + sum[x][c] - i.p;
if (dist[i.v] == -1 or dist[i.v] > nd) {
pq.push(pii(nd,pi(i.v,0)));
dist[i.v] = nd;
}
}
} else {
if (d != dist[x]) continue;
for (auto i: adjlist[x]) {
int nd = d + i.p;
//Take a (1)
//Straight to dist
if (dist[i.v] == -1 or dist[i.v] > nd) {
dist[i.v] = nd;
pq.push(pii(nd,pi(i.v,0)));
}
//Do a suspension
nd = d;
if (dp[i.v].count(i.c) == 0 or dp[i.v][i.c] > nd) {
dp[i.v][i.c] = nd;
pq.push(pii(nd,pi(i.v,i.c)));
}
//Take a (2)
nd = d + sum[x][i.c] - i.p;
if (dist[i.v] == -1 or dist[i.v] > nd) {
dist[i.v] = nd;
pq.push(pii(nd,pi(i.v,0)));
}
}
}
}
cout << dist[n];
}
